Heroin self-administration: an operant analysis.
D003216:Conditioning, Operant / Q000187:drug effects; D004195:Disease Models, Animal; D006556:Heroin Dependence / Q000523:psychology*; D006801:Humans; D008297:Male; D009271:Naltrexone / Q000494:pharmacology; D010919:Placebos; D012055:Reinforcement Schedule; D012646:Self Administration
D010919:Placebos; D009271:Naltrexone