00345nam a2200121Ia 4500008004100000020001800041082001800059100002400077245003300101260004000134300002500174500002400199250307b        |||||||| |||| 00| 0 eng d  a9783110226737  a511.6bK45.PC  aKheyfits, Alexander  aA primer in combinatoricsb/  aNew York:bWalter de Gruyter,c2010  ax, 323p. Bibl. Index  aDe Gruyter Textbook