About: http://dbpedia.org/resource/Lucky%E2%80%99s_Collectors_Guide_to_20th_Century_Yo-Yos

Lucky’s Collectors Guide to 20th Century Yo-Yos is a catalog of yo-yos manufactured largely in the United States from the twentieth century. Produced by Lucky Meisenheimer, M.D. , the Guinness World Record holder for the largest Yo-Yo collection, the book features the history of the yo-yo as well as a price guide. Over one thousand photographs of yo-yos and memorabilia are listed in the book. Collectors frequently use his numbering system to indentify particular yo-yos.