Francesco M. Malvestuto Mauro Mezzini Marina Moscarini Minimal invariant sets in a vertex-weighted graph. 140-161 2006 362 Theor. Comput. Sci. 1-3 http://dx.doi.org/10.1016/j.tcs.2006.06.005 db/journals/tcs/tcs362.html#MalvestutoMM06