TY  - BOOK
AU  - Hajnal A
AU  -  Sos Vera T
TI  - Combinatorics
T2  - Colloquia mathematica societatis janos bolyai; 18
U1  - B217, L8.1-;L8.2 
PY  - 1978///
CY  - Amsterdam
PB  - North-Holland Publisher        
KW  - Combinatorics
ER  -