Anderson TM, vonHoldt BM, Candille SI, Musiani M, Greco C, Stahler DR, Smith DW, Padhukasahasram B, Randi E, Leonard JA, Bustamante CD, Ostrander EA, Tang H, Wayne RK, Barsh GS. Molecular and evolutionary history of melanism in North American gray wolves. Science. 2009 Mar 6;323(5919):1339-43. doi: 10.1126/science.1165448. Epub 2009 Feb 5. PMID: 19197024; PMCID: PMC2903542.