One of the most heavily marked books is Magic: History, Theory and Practice (1923), by Ernst Schertel. When I typed the author's name into one Internet search engine, I scored eight hits, including sites on Satanism, eroticism, sadomasochism, and flagellation. When I typed his name into Google, I scored twenty-six hits, including sites on parapsychology, astrology, and diverse sexual practices. According to a Web site for Germany's sadomasochistic community, Schertel wrote numerous books on flagellation and eroticism, and was "a central figure" in the German nudist movement of the 1920s and 1930s.