Kunkel, K. E., Palecki, M., Ensor, L., Hubbard, K. G., Robinson, D., Redmond, K. T., Easterling, D. (2009). Trends in Twentieth-Century U.S. Snowfall Using a Quality-Controlled Dataset, J. Atmos. Ocean Tech., 26 (1), 33-44, DOI: 10.1175/2008JTECHA1138.1.