00398nam a22001457a 4500020001800000100001900018245004600037250000700083260004000090300001300130490004100143650002500184650001700209650002600226  a9789349750302  aWagner, Carl G  aFirst course in enumerative combinatorics  a49  aTelanganabUniversities pressc2020  axvii+272  aPure and applied undergraduate texts  aBinomial coefficient  aVector space  aPartially ordered set