Keywords: Odhner 239 calculator - Ridai Museum of Modern Science, Tokyo - DSC07622.JPG en Exhibit in the Ridai Museum of Modern Science Tokyo University of Science Kagurazaka campus - 1-3 Kagurazaka Shinjuku-ku Tokyo 2015-02-20 02 18 18 own Daderot other versions cc-zero Odhner calculators in the Ridai Museum of Modern Science |