TY  - BOOK
AU  - Hartsfield,Nora
AU  - Ringel,Gerhard
TI  - Pearls in graph theory : :  a comprehensive introduction,
SN  - 0123285534
PY  - 1994///
CY  - Boston, Mass. : 
PB  -  Academic Press, 
KW  - Graph theory
N1  - p. 241-244
ER  -