On the connectivity of minimum and minimal counterexamples to Hadwiger's Conjecture.

Ken-ichi Kawarabayashi On the connectivity of minimum and minimal counterexamples to Hadwiger's Conjecture. 144-150 2007 97 J. Comb. Theory, Ser. B 1 http://dx.doi.org/10.1016/j.jctb.2006.04.004 db/journals/jct/jctb97.html#Kawarabayashi07