Xiao Zhou Shin-Ichi Nakano Hitoshi Suzuki Takao Nishizeki An Efficient Algorithm for Edge-Coloring Series-Parallel Multigraphs. 516-529 1992 conf/latin/1992 LATIN db/conf/latin/latin92.html#ZhouNSN92 http://dx.doi.org/10.1007/BFb0023853