title: Drug patents: the evergreening problem.
authors: Roger
authors: R
authors: Collier
mesh_terms: D004345:Drug Industry / Q000331:legislation & jurisprudence; D016568:Drugs, Generic; D015507:Drugs, Investigational; D006801:Humans; D007194:India; D007880:Legislation, Drug; D010330:Patents as Topic / Q000331:legislation & jurisprudence*
chemical_list: D016568:Drugs, Generic; D015507:Drugs, Investigational