Anthony S. Fischbach (U.S. Geological Survey),Daniel H. Monson (U.S. Geological Survey),Chadwick V. Jay (U.S. Geological Survey) 2009: Enumeration of Pacific Walrus Carcasses on Beaches of the Chukchi Sea in Alaska Following a Mortality Event, September 2009. Open-File Report 2009-1291, <http://pubs.usgs.gov/of/2009/1291/>