Thomas Böhme Ken-ichi Kawarabayashi John Maharry Bojan Mohar Linear connectivity forces large complete bipartite minors: [J. Combin. Theory Ser. B Vol. 99(2)] 323 2009 99 http://dx.doi.org/10.1016/S0095-8956(08)00162-7 J. Comb. Theory, Ser. B 2 db/journals/jct/jctb99.html#BohmeKMM09