Ken-ichi Kawarabayashi Bruce A. Reed Orlando Lee Removable cycles in non-bipartite graphs. 30-38 2009 99 J. Comb. Theory, Ser. B 1 http://dx.doi.org/10.1016/j.jctb.2008.03.007 db/journals/jct/jctb99.html#KawarabayashiRL09