@article{EXMA_2006__15_3_223876, author = {Lundow, P.H. and Markstr\"om, K.}, title = {Broken-cycle-free subgraphs and the log-concavity conjecture for chromatic polynomials.}, journal = {Experimental mathematics}, pages = {343--353}, publisher = {mathdoc}, volume = {15}, number = {3}, year = {2006}, zbl = {1120.05032}, language = {en}, url = {http://geodesic.mathdoc.fr/item/EXMA_2006__15_3_223876/} }