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  - Includes bibliographical references (p. 241-244) and index; Basic graph theory--Colorings of graphs--Circuits and cycles--External problems
ER  -