Hans-Joachim Böckenhauer Dirk Bongartz Juraj Hromkovic Ralf Klasing Guido Proietti Sebastian Seibert Walter Unger On the hardness of constructing minimal 2-connected spanning subgraphs in complete graphs with sharpened triangle inequality. 137-153 2004 326 Theor. Comput. Sci. 1-3 http://dx.doi.org/10.1016/j.tcs.2004.06.019 db/journals/tcs/tcs326.html#BockenhauerBHKPSU04