W. W. Rouse (Walter William Rouse) Ball
Mathematical Recreations and Essays
W. W. Rouse (Walter William Rouse) Ball · 2008
ספרייה ציבורית, Project Gutenberg. בלי הרשמה.
Numbers, PrimeAstrologyMatterMathematical recreationsGeometry -- Famous problemsCryptographyCiphersSpace and time