Stavros D. Nikolopoulos Leonidas Palios Maximum-Size Subgraphs of P4-Sparse Graphs Admitting a Perfect Matching. 68-79 2005 conf/pci/2005 Panhellenic Conference on Informatics http://dx.doi.org/10.1007/11573036_7 db/conf/pci/pci2005.html#NikolopoulosP05