academic article

• Suarez, J., Khom, S., Alen, F., Natividad, L. A., Varodayan, F. P., Patel, R. R., Kirson, D., Arco, R., Ballesta, A., Bajo, M., Rubio, L., Martin-Fardon, R., et al. Cessation of fluoxetine treatment increases alcohol seeking during relapse and dysregulates endocannabinoid and glutamatergic signaling in the central amygdala Addiction Biology  2020  DOI:10.1111/adb.12813  PMID:31339221
• Matzeu, A., Martin-Fardon, R. Targeting the Orexin System for Prescription Opioid Use Disorder Brain Sciences  2020 10  DOI:10.3390/brainsci10040226  PMID:32290110  PMCID:PMC7225970
• Matzen, A., Martin-Fardon, R. Targeting the orexin system for prescription opioid use disorder: Orexin-1 receptor blockade prevents oxycodone taking and seeking in rats Neuropharmacology  2020 164  DOI:10.1016/j.neuropharm.2019.107906  PMID:31841797  PMCID:PMC69544966
• Kim, J. S., Martin-Fardon, R. Possible role of CRF-Hcrt interaction in the infralimbic cortex in the emergence and maintenance of compulsive alcohol-seeking behavior Alcoholism-Clinical and Experimental Research  2020  DOI:10.1111/acer.14264  PMID:31840823
• Matzeu, A., Martin-Fardon, R. Blockade of Orexin Receptors in the Posterior Paraventricular Nucleus of the Thalamus Prevents Stress-Induced Reinstatement of Reward-Seeking Behavior in Rats With a History of Ethanol Dependence Frontiers in Integrative Neuroscience  2020 14  DOI:10.3389/fnint.2020.599710  PMID:33240054  PMCID:PMC7683390
• Pavon, F. J., Polis, I., Stouffer, D. G., Roberto, M., Martin-Fardon, R., de Fonseca, F. R., Parsons, L. H., Serrano, A. COX-2 Inhibition Antagonizes Intra-Accumbens 2-Arachidonoylglycerol-Mediated Reduction in Ethanol Self-Administration in Rats Alcoholism-Clinical and Experimental Research  2020  DOI:10.1111/acer.14456  PMID:32944989
• Pavon, F. J., Serrano, A., Stouffer, D. G., Polis, I., Roberto, M., Cravatt, B. F., Martin-Fardon, R., de Fonseca, F. R., Parsons, L. H. Ethanol-induced alterations in endocannabinoids and relevant neurotransmitters in the nucleus accumbens of fatty acid amide hydrolase knockout mice Addiction Biology  2019 24:1204-1215  DOI:10.1111/adb.12695  PMID:30421483  PMCID:PMC6551299
• Matzeu, A., Terenius, L., Martin-Fardon, R. Exploring sex differences in the attenuation of ethanol drinking by naltrexone in dependent rats during early and protracted abstinence Alcoholism-Clinical and Experimental Research  2018 42:2466-2478  DOI:10.1111/acer.13898  PMID:30320880  PMCID:PMC6286204
• Schmeichel, B. E., Matzeu, A., Koebel, P., Vendruscolo, L. F., Sidhu, H., Shahryari, R., Kieffer, B. L., Koob, G. F., Martin-Fardon, R., Contet, C. Knockdown of hypocretin attenuates extended access of cocaine self-administration in rats Neuropsychopharmacology  2018 43:2373-2382  DOI:10.1038/s41386-018-0054-4  PMID:29703996  PMCID:PMC6180106
• Natividad, L. A., Steinman, M. Q., Laredo, S. A., Irimia, C., Polis, I. Y., Lintz, R., Buczynski, M. W., Martin-Fardon, R., Roberto, M., Parsons, L. H. Phosphorylation of calcium/calmodulin-dependent protein kinase II in the rat dorsal medial prefrontal cortex is associated with alcohol-induced cognitive inflexibility Addiction Biology  2018 23:1117-1129  DOI:10.1111/adb.12568  PMID:28940879  PMCID:PMC5862723
• Gonzalez-Cuevas, G., Martin-Fardon, R., Kerr, T. M., Stouffer, D. G., Parsons, L. H., Hammell, D. C., Banks, S. L., Stinchcomb, A. L., Weiss, F. Unique treatment potential of cannabidiol for the prevention of relapse to drug use: preclinical proof of principle Neuropsychopharmacology  2018 43:2036-2045  DOI:10.1038/s41386-018-0050-8  PMID:29686308  PMCID:PMC6098033
• Matzeu, A., Martin-Fardon, R. Drug seeking and relapse: new evidence of a role for orexin and dynorphin co-transmission in the paraventricular nucleus of the thalamus Frontiers in Neurology  2018 9  DOI:10.3389/fneur.2018.00720
• Serrano, A., Pavon, F. J., Buczynski, M. W., Schlosburg, J., Natividad, L. A., Polis, I. Y., Stouffer, D. G., Zorrilla, E. P., Roberto, M., Cravatt, B. F., Martin-Fardon, R., de Fonseca, F. R., et al. Deficient endocannabinoid signaling in the central amygdala contributes to alcohol dependence-related anxiety-like behavior and excessive alcohol intake Neuropsychopharmacology  2018 43:1840-1850  DOI:10.1038/s41386-018-0055-3  PMID:29748627  PMCID:PMC6046053
• Matzeu, A., Kallupi, M., George, O., Schweitzer, P., Martin-Fardon, R. Dynorphin counteracts orexin in the paraventricular nucleus of the thalamus: cellular and behavioral evidence Neuropsychopharmacology  2018 43:1010-1020  DOI:10.1038/npp.2017.250  PMID:29052613  PMCID:PMC5854806
• Pavon, F. J., Serrano, A., Sidhpura, N., Polis, I., Stouffer, D., de Fonseca, F. R., Cravatt, B. F., Martin-Fardon, R., Parsons, L. H. Fatty acid amide hydrolase (FAAH) inactivation confers enhanced sensitivity to nicotine-induced dopamine release in the mouse nucleus accumbens Addiction Biology  2018 23:723-734  DOI:10.1111/adb.12531  PMID:28660730  PMCID:PMC5747548
• de Guglielmo, G., Matzeu, A., Kononoff, J., Mattioni, J., Martin-Fardon, R., George, O. Cebranopadol blocks the escalation of cocaine intake and conditioned reinstatement of cocaine seeking in rats Journal of Pharmacology and Experimental Therapeutics  2017 362:378-384  DOI:10.1124/jpet.117.241042  PMID:28645915  PMCID:PMC5539589
• Matzeu, A., Kerr, T. M., Weiss, F., Martin-Fardon, R. Orexin-A/hypocretin-1 mediates cocaine-seeking behavior in the posterior paraventricular nucleus of the thalamus via orexin/hypocretin receptor-2 Journal of Pharmacology and Experimental Therapeutics  2016 359:273-279  DOI:10.1124/jpet.116.235945  PMID:27540003  PMCID:PMC5074483
• Martin-Fardon, R., Cauvi, G., Kerr, T. M., Weiss, F. Differential role of hypothalamic orexin/hypocretin neurons in reward seeking motivated by cocaine versus palatable food Addiction Biology  2016 23:6-15  DOI:10.1111/adb.12441  PMID:27558790  PMCID:PMC5325827
• Martin-Fardon, R., Weiss, F. Perseveration of craving: effects of stimuli conditioned to drugs of abuse versus conventional reinforcers differing in demand Addiction Biology  2016 22:923-932  DOI:10.1111/adb.12374  PMID:26864474  PMCID:PMC4980277
• Matzeu, A., Weiss, F., Martin-Fardon, R. Transient inactivation of the posterior paraventricular nucleus of the thalamus blocks cocaine-seeking behavior Neuroscience Letters  2015 608:34-39  DOI:10.1016/j.neulet.2015.10.016  PMID:26455867  PMCID:PMC4639449
• de Guglielmo, G., Martin-Fardon, R., Teshima, K., Ciccocioppo, R., Weiss, F. MT-7716, a potent NOP receptor agonist, preferentially reduces ethanol seeking and reinforcement in post-dependent rats Addiction Biology  2015 20:643-651  DOI:10.1111/adb.12157  PMID:24930632  PMCID:PMC4268094
• Matzeu, A., Cauvi, G., Kerr, T. M., Weiss, F., Martin-Fardon, R. The paraventricular nucleus of the thalamus is differentially recruited by stimuli conditioned to the availability of cocaine versus palatable food Addiction Biology  2015 22:70-77  DOI:10.1111/adb.12280  PMID:26096647  PMCID:PMC4788574
• Martin-Fardon, R., Weiss, F. Blockade of hypocretin receptor-1 preferentially prevents cocaine seeking: comparison with natural reward seeking Neuroreport  2014 25:485-488  DOI:10.1097/wnr.0000000000000120  PMID:24407199  PMCID:PMC3981907
• Matzeu, A., Zamora-Martinez, E. R., Martin-Fardon, R. The paraventricular nucleus of the thalamus is recruited by both natural rewards and drugs of abuse: recent evidence of a pivotal role for orexin/hypocretin signaling in this thalamic nucleus in drug-seeking behavior Frontiers in Behavioral Neuroscience  2014 8:117  DOI:10.3389/fnbeh.2014.00117  PMID:24765071  PMCID:PMC3982054
• Aujla, H., Cannarsa, R., Romualdi, P., Ciccocioppo, R., Martin-Fardon, R., Weiss, F. Modification of anxiety-like behaviors by nociceptin/orphanin FQ (N/OFQ) and time-dependent changes in N/OFQ-NOP gene expression following ethanol withdrawal Addiction Biology  2013 18:467-479  DOI:10.1111/j.1369-1600.2012.00466.x  PMID:22804785  PMCID:PMC3477306
• Martin-Fardon, R., Weiss, F. Modeling relapse in animals Current topics in behavioral neurosciences  2013 13:403-32  DOI:10.1007/7854_2012_202  PMID:22389178
• Martin-Fardon, R., Boutrel, B. Orexin/hypocretin (Orx/Hcrt) transmission and drug-seeking behavior: is the paraventricular nucleus of the thalamus (PVT) part of the drug seeking circuitry? Frontiers in Behavioral Neuroscience  2012 6:75  DOI:10.3389/fnbeh.2012.00075  PMID:23162448  PMCID:PMC3494007
• Martin-Fardon, R., Strong, E. M., Weiss, F. Effect of sigma(1) receptor antagonism on ethanol and natural reward seeking Neuroreport  2012 23:809-813  DOI:10.1097/WNR.0b013e32835717c8  PMID:22878224
• Martin-Fardon, R., Weiss, F. (-)-2-oxa-4-aminobicylco[3.1.0]hexane-4,6-dicarboxylic acid (LY379268) and 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]piperidine (MTEP) similarly attenuate stress-induced reinstatement of cocaine seeking Addiction Biology  2012 17:557-564  DOI:10.1111/j.1369-1600.2011.00345.x  PMID:21790902  PMCID:PMC3204322
• Martin-Fardon, R., Weiss, F. N-(2-methyl-6-benzoxazolyl)-N'-1,5-naphthyridin-4-yl urea (SB334867), a hypocretin receptor-1 antagonist, preferentially prevents ethanol seeking: comparison with natural reward seeking Addiction Biology  2012  DOI:10.1111/j.1369-1600.2012.00480.x  PMID:22830647  PMCID:PMC3491173
• Kufahl, P. R., Martin-Fardon, R., Weiss, F. Enhanced sensitivity to attenuation of conditioned reinstatement by the mGluR 2/3 agonist LY379268 and increased functional activity of mGluR 2/3 in rats with a history of ethanol dependence Neuropsychopharmacology  2011 36:2762-2773  DOI:10.1038/npp.2011.174  PMID:21881571  PMCID:PMC3230501
• Economidou, D., Cippitelli, A., Stopponi, S., Braconi, S., Clementi, S., Ubaldi, M., Martin-Fardon, R., Weiss, F., Massi, M., Ciccocioppo, R. Activation of brain NOP receptors attenuates acute and protracted alcohol withdrawal symptoms in the rat Alcoholism-Clinical and Experimental Research  2011 35:747-755  DOI:10.1111/j.1530-0277.2010.01392.x  PMID:21223310  PMCID:PMC3066303
• Hao, Y., Martin-Fardon, R., Weiss, F. Behavioral and functional evidence of metabotropic glutamate receptor 2/3 and metabotropic glutamate receptor 5 dysregulation in cocaine-escalated rats: Factor in the transition to dependence Biological Psychiatry  2010 68:240-248  DOI:10.1016/j.biopsych.2010.02.011  PMID:20416862  PMCID:PMC2907426
• Sidhpura, N., Weiss, F., Martin-Fardon, R. Effects of the mGlu2/3 agonist LY379268 and the mGlu5 antagonist MTEP on ethanol seeking and reinforcement are differentially altered in rats with a history of ethanol dependence Biological Psychiatry  2010 67:804-811  DOI:10.1016/j.biopsych.2010.01.005  PMID:20189165  PMCID:PMC2854322
• Braconi, S., Sidhpura, N., Aujla, H., Martin-Fardon, R., Weiss, F., Ciccocioppo, R. Revisiting intragastric ethanol intubation as a dependence induction method for studies of ethanol reward and motivation in rats Alcoholism-Clinical and Experimental Research  2010 34:538-544  DOI:10.1111/j.1530-0277.2009.01119.x  PMID:20028350  PMCID:PMC2858236
• Martin-Fardon, R., Zorrilla, E. P., Ciccocioppo, R., Weiss, F. Role of innate and drug-induced dysregulation of brain stress and arousal systems in addiction: Focus on corticotropin-releasing factor, nociceptin/orphanin FQ, and orexin/hypocretin Brain Research  2010 1314:145-161  DOI:10.1016/j.brainres.2009.12.027  PMID:20026088  PMCID:PMC2819635
• Martin-Fardon, R., Baptista, M. A. S., Dayas, C. V., Weiss, F. Dissociation of the effects of MTEP [3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]piperidine] on conditioned reinstatement and reinforcement: comparison between cocaine and a conventional reinforcer Journal of Pharmacology and Experimental Therapeutics  2009 329:1084-1090  DOI:10.1124/jpet.109.151357  PMID:19258516  PMCID:PMC2683783
• Economidou, D., Hansson, A. C., Weiss, F., Terasmaa, A., Sommer, W. H., Cippitelli, A., Fedeli, A., Martin-Fardon, R., Massi, M., Ciccocioppo, R., Heilig, M. Dysregulation of nociceptin/orphanin FQ activity in the amygdala is linked to excessive alcohol drinking in the rat Biological Psychiatry  2008 64:211-218  DOI:10.1016/j.biopsych.2008.02.004  PMID:18367152  PMCID:PMC4275225
• Aujla, H., Martin-Fardon, R., Weiss, F. Rats with extended access to cocaine exhibit increased stress reactivity and sensitivity to the anxiolytic-like effects of the mGluR 2/3 agonist LY379268 during abstinence Neuropsychopharmacology  2008 33:1818-1826  DOI:10.1038/sj.npp.1301588  PMID:17895914
• Martin-Fardon, R., Ciccocioppo, R., Aujla, H., Weiss, F. The dorsal subiculum mediates the acquisition of conditioned reinstatement of cocaine-seeking Neuropsychopharmacology  2008 33:1827-1834  DOI:10.1038/sj.npp.1301589  PMID:17957218
• Dayas, C. V., McGranahan, T. M., Martin-Fardon, R., Weiss, F. Stimuli linked to ethanol availability activate hypothalamic CART and orexin neurons in a reinstatement model of relapse Biological Psychiatry  2008 63:152-157  DOI:10.1016/j.biopsych.2007.02.002  PMID:17570346
• Gonzalez-Cuevas, G., Aujla, H., Martin-Fardon, R., Lopez-Moreno, J. A., Navarro, M., Weiss, F. Subchronic cannabinoid agonist (WIN 55,212-2) treatment during cocaine abstinence alters subsequent cocaine seeking behavior Neuropsychopharmacology  2007 32:2260-2266  DOI:10.1038/sj.npp.1301365  PMID:17392740
• Martin-Fardon, R., Maurice, T., Aujla, H., Bowen, W. D., Weiss, F. Differential effects of sigma(1) receptor blockade on self-administration and conditioned reinstatement motivated by cocaine vs natural reward Neuropsychopharmacology  2007 32:1967-1973  DOI:10.1038/sj.npp.1301323  PMID:17268407
• Economidou, D., Fedeli, A., Fardon, R. M., Weiss, F., Massi, M., Ciccocioppo, R. Effect of novel nociceptin/orphanin FQ-NOP receptor ligands on ethanol drinking in alcohol-preferring msP rats Peptides  2006 27:3299-3306  DOI:10.1016/j.peptides.2006.09.007  PMID:17097763  PMCID:PMC1847604
• Zhao, Y., Dayas, C. V., Aujla, H., Baptista, M. A. S., Martin-Fardon, R., Weiss, F. Activation of group II metabotropic glutamate receptors attenuates both stress and cue-induced ethanol-seeking and modulates c-fos expression in the hippocampus and amygdala Journal of Neuroscience  2006 26:9967-9974  DOI:10.1523/jneurosci.2384-06.2006  PMID:17005860
• Boutrel, B., Kenny, P. J., Specio, S. E., Martin-Fardon, R., Markou, A., Koob, G. F., de Lecea, L. Role for hypocretin in mediating stress-induced reinstatement of cocaine-seeking behavior Proceedings of the National Academy of Sciences of the United States of America  2005 102:19168-19173  DOI:10.1073/pnas.0507480102  PMID:16357203  PMCID:PMC1323172
• Martin-Fardon, R., Lorentz, C. U., Stuempfig, N. D., Weiss, F. Priming with BTCP, a dopamine reuptake blocker, reinstates cocaine-seeking and enhances cocaine cue-induced reinstatement Pharmacology, Biochemistry and Behavior  2005 82:46-54  DOI:10.1016/j.pbb.2005.07.010  PMID:16099021
• Romieu, P., Meunier, J., Garcia, D., Zozime, N., Martin-Fardon, R., Bowen, W. D., Maurice, T. The sigma(1) (sigma(1)) receptor activation is a key step for the reactivation of cocaine conditioned place preference by drug priming Psychopharmacology  2004 175:154-162  DOI:10.1007/s00213-004-1814-x  PMID:14985920
• Baptista, M. A. S., Martin-Fardon, R., Weiss, F. Preferential effects of the metabotropic glutamate 2/3 receptor agonist LY379268 on conditioned reinstatement versus primary reinforcement: comparison between cocaine and a potent conventional reinforcer Journal of Neuroscience  2004 24:4723-4727  DOI:10.1523/jneurosci.0176-04.2004  PMID:15152032
• Dayas, C. V., Martin-Fardon, R., Thorsell, A., Weiss, F. Chronic footshock, but not a physiological stressor, suppresses the alcohol deprivation effect in dependent rats Alcohol and Alcoholism  2004 39:190-196  DOI:10.1093/alcalc/agh046  PMID:15082455
• Ciccocioppo, R., Martin-Fardon, R., Weiss, F. Stimuli associated with a single cocaine experience elicit longlasting cocaine-seeking Nature Neuroscience  2004 7:495-496  DOI:10.1038/nn1219  PMID:15048121
• Martin-Fardon, R., Lorentz, C. U., Kamenka, J. M., Weiss, F. 3-OH-pip-BTCP, a metabolite of the potent DA uptake blocker BTCP, exerts cocaine-like action in rats Neuroreport  2003 14:2439-2444  DOI:10.1097/01.wnr.0000099608.19426.39  PMID:14663207
• Ciccocioppo, R., Lin, D., Martin-Fardon, R., Weiss, F. Reinstatement of ethanol-seeking behavior by drug cues following single versus multiple ethanol intoxication in the rat: Effects of naltrexone Psychopharmacology  2003 168:208-215  DOI:10.1007/s00213-002-1380-z  PMID:12664190
• Romieu, P., Martin-Fardon, R., Bowen, W. D., Maurice, T. Sigma(1) receptor-related neuroactive steroids modulate cocaine-induced reward Journal of Neuroscience  2003 23:3572-3576  PMID:12736327
• Izzo, E., Martin-Fardon, R., Koob, G. F., Weiss, F., Sanna, P. P. Neural plasticity and addiction: PI3-kinase and cocaine behavioral sensitization Nature Neuroscience  2002 5:1263-1264  DOI:10.1038/nn977  PMID:12436114
• Ciccocioppo, R., Martin-Fardon, R., Weiss, F. Effect of selective blockade of mu(1) or delta opioid receptors on reinstatement of alcohol-seeking behavior by drug-associated stimuli in rats Neuropsychopharmacology  2002 27:391-399  DOI:10.1016/s0893-133x(02)00302-0  PMID:12225696
• Maurice, T., Martin-Fardon, R., Romieu, P., Matsumoto, R. R. Sigma(1) (sigma(1)) receptor antagonists represent a new strategy against cocaine addiction and toxicity Neuroscience and Biobehavioral Reviews  2002 26:499-527  DOI:10.1016/S0149-7634(02)00017-9  PMID:12204195
• Martin-Fardon, R., Weiss, F. BTCP is a potent reinforcer in rats: comparison of behavior maintained on fixed- and progressive-ratio schedules Pharmacology, Biochemistry and Behavior  2002 72:343-353  DOI:10.1016/s0091-3057(01)00764-x  PMID:11900805
• Romieu, P., Phan, V. L., Martin-Fardon, R., Maurice, T. Involvement of the sigma(1) receptor in cocaine-induced conditioned place preference: Possible dependence on dopamine uptake blockade Neuropsychopharmacology  2002 26:444-455  DOI:10.1016/s0893-133x(01)00391-8  PMID:11927169
• Martin-Fardon, R., Kerr, T. M., Deleuze-Masquefa, C., Kamenka, J. M., Weiss, F. Behavioral and neurochemical effects of 3-OH-pip-BTCP, an active metabolite of BTCP in rats Neuroreport  2001 12:4165-4169  DOI:10.1097/00001756-200112210-00060  PMID:11742258
• Weiss, F., Martin-Fardon, R., Ciccocioppo, R., Kerr, T. M., Smith, D. L., Ben-Shahar, O. Enduring resistance to extinction of cocaine-seeking behavior induced by drug-related cues Neuropsychopharmacology  2001 25:361-372  DOI:10.1016/s0893-133x(01)00238-x  PMID:11522464
• Ciccocioppo, R., Martin-Fardon, R., Weiss, F., Massi, M. Nociceptin/orphanin FQ inhibits stress- and CRF-induced anorexia in rats Neuroreport  2001 12:1145-1149  DOI:10.1097/00001756-200105080-00019  PMID:11338181
• Romieu, P., Martin-Fardon, R., Maurice, T. Involvement of the sigma(1) receptor in the cocaine-induced conditioned place preference Neuroreport  2000 11:2885-2888  DOI:10.1097/00001756-200009110-00011  PMID:11006959
• Martin-Fardon, R., Weiss, F. N-[1-(2-benzo[b]thiophenyl)Cyclohexyl]- piperidine (BTCP) exerts cocaine-like actions on drug-maintained responding in rats Neuropsychopharmacology  2000 23:316-325  DOI:10.1016/s0893-133x(00)00104-4  PMID:10942855
• Martin-Fardon, R., Ben-Shahar, O., Weiss, F. Non reciprocal cross-sensitization between cocaine and BTCP on locomotor activity in the rat Pharmacology, Biochemistry and Behavior  2000 66:631-635  DOI:10.1016/s0091-3057(00)00262-8  PMID:10899381
• Martin-Fardon, R., Ciccocioppo, R., Massi, M., Weiss, F. Nociceptin prevents stress-induced ethanol- but not cocaine-seeking behavior in rats Neuroreport  2000 11:1939-1943  DOI:10.1097/00001756-200006260-00026  PMID:10884047
• Martin-Fardon, R., Sandillon, F., Thibault, J., Privat, A., Vignon, J. Long-term monitoring of extracellular dopamine concentration in the rat striatum by a repeated microdialysis procedure Journal of Neuroscience Methods  1997 72:123-135  DOI:10.1016/s0165-0270(96)02170-x  PMID:9133576
• Martin-Fardon, R., Arnaud, M., Rousseau, E., Kamenka, J. M., Privat, A., Vignon, J. N-[1-(2-Benzo(b)thiophenyl)cyclohexyl]piperidine (BTCP) and cocaine induce similar effects on striatal dopamine: a microdialysis study in freely moving rats Neuroscience Letters  1996 211:179-182  DOI:10.1016/0304-3940(96)12744-0  PMID:8817570
• Coderc, E., Martin-Fardon, R., Vignon, J., Kamenka, J. M. New compounds resulting from structural and biochemical similarities between GBR 1278 and BTCP, two potent inhibitors of dopamine uptake European Journal of Medicinal Chemistry  1993 28:893-898  DOI:10.1016/0223-5234(93)90042-d