Shuji Isobe Xiao Zhou Takao Nishizeki Total Colorings of Degenerated Graphs. 506-517 2001 conf/icalp/2001 ICALP http://link.springer.de/link/service/series/0558/bibs/2076/20760506.htm db/conf/icalp/icalp2001.html#IsobeZN01