Vilenkin, N.Ja. <br/><br/>
Combinatorial mathematics for recreation;:  translated from the russian by George Yankovsky/ 
N. Ja. Vilenkin. 
 - [1st ed.] 
 - Moscow:  MIR,  1969. 
 - 207 p. 
<br/><br/><label>Dewey Class. No.: </label>511.6  / V699c