title: Half a century of challenges.
authors: Arne
authors: A
authors: Ljungqvist
mesh_terms: D056352:Athletes / Q000331:legislation & jurisprudence*; D004300:Doping in Sports / Q000266:history / Q000331:legislation & jurisprudence* / Q000639:trends; D049673:History, 20th Century; D006801:Humans; D007390:International Agencies; D058573:Performance-Enhancing Substances / Q000032:analysis* / Q000266:history; D013177:Sports / Q000331:legislation & jurisprudence*
chemical_list: D058573:Performance-Enhancing Substances