An anonymous buyer paid 28,000 pounds ($51,000, 35,200 euros) Wednesday at a London auction for a rare signed first edition of Adolf Hitler's "Mein Kampf" (My struggle). The book is thought to have been found in one of the Nazi leader's offices after the end of World War II. Published in 1925 it is a blend of autobiography and political tract. At the time of writing it Hitler was in jail for mounting an unsuccessful coup. About 500 copies of the first edition were printed. In the book Hitler elaborates his views on Aryan racial purity, hatred of Jews and rejection of communism.