This photograph shows a Tibetan doctor standing on the roof of his house holding two precious medical books. One is a copy of the fundamental Tibetan medical classic Gyu Shi ('Four Tantras') written in the 12th century; the other is a manuscript on compounding medicines, which was composed by the members of his medical family (going back four generations) and takes into account the knowledge the doctors of this lineage have gained through trial and error. The photo was taken in the Tibetan Autonomous Region, China, in 2003. [ Wellcome Image Awards