title: Self-administration of cigarettes with varying tobacco and nicotine content.
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000032:analysis*; D010947:Plants, Toxic; D012646:Self Administration; D012907:Smoking / Q000523:psychology*; D014026:Nicotiana / Q000032:analysis*
chemical_list: D009538:Nicotine