Xiaolong Huang Zemin Jin Xingxing Yu Xiaoyan Zhang Contractible Cliques in <i>k</i>-Connected Graphs. 361-370 2006 22 Graphs and Combinatorics 3 http://dx.doi.org/10.1007/s00373-006-0670-3 db/journals/gc/gc22.html#HuangJYZ06