TY  - BOOK
AU  - Wallis W D
AU  - George J C
TI  - Introduction to combinatorics
SN  - 978-1-4398-0622-7
U1  - 511.6 
PY  - 2011///
CY  - Boca Raton
PB  - CRC Press
KW  - Combinatorial analysis
ER  -