Ruei-Yuan Chang Guanling Lee Sheng-Lung Peng Minimum Vertex Ranking Spanning Tree Problem on Some Classes of Graphs. 758-765 2008 ICIC (2) http://dx.doi.org/10.1007/978-3-540-85984-0_91 conf/icic/2008-2 db/conf/icic/icic2008-2.html#ChangLP08