Alvarez, D.A., Shappell, N.W., Billey, L.O., Bermudez, D.S., Wilson, V.S., Kolpin, D.W., Perkins, S.D., Evans, N., Foreman, W.T., Gray, J.L., Shipitalo, M.J., Meyer, M.T. 2013. Bioassay of estrogenicity and chemical analysis of estrogens in streams across the United States associated with livestock operations. Water Research. 47:3347-3363.
Dammann, A.A., Shappell, N.W., Billey, L.O., Bartell, S.E., Schoenfuss, H.L. 2011. Comparing biological effects of estrone (E1) and 17B-estradiol (E2) in mature fathead minnows. Joint Meeting of the Midwest Society of Environmental Toxicology and Chemistry and the Chicago Regional Chapter of Society for Risk Analysis, March 23-24, 2011, Lake Geneva, WI.
Billey, L.O., Shipitalo, M.J., Owens, L.B., Shappell, N.W. 2010. Estrogenic activity in runoff – effect of animal waste-based fertilizer application to frozen fields. Midwest Chapter Society of Environmental Toxicology and Chemistry Abstracts, March 24-26, 2010, St. Paul, MN. Available:http://www.midwestsetac.org/2010%20abstracts/Estrogenic%20activity%20in%20runoff%20–%20effect%20of%20animal%20waste-based%20fertilizer%20application%20to%20frozen%fields, %20Billey.pdf.
Shappell, N.W., Billey, L.O., Elder, K.H. 2009. Estrogenic Activity and Estrogens of Surface Waters in Proximity to a Large Dairy. Society of Environmental Toxicology and Chemistry (SETAC)Abstract Book, New Orleans, LA, November 19-23, 2009. Abstract 31, page 11.
Shappell, N.W., Billey, L.O. 2004. Assessment of tasco and ycwp on ergovaline toxicity in caco-2 cells. [abstract] Joint Meeting of American Society of Animal Science, American Dairy Science Association, and Poultry Science Association, St. Louis, MO, July 25-29, 2004, Journal of Animal Science 82(Suppl 1):181, Abstract T72.
Shappell, N.W., Billey, L.O., Feil, V.J. 2002. Effect of clenbuterol on body stores of polychlorinated dibenzofurans (PCDFs) and dibenzo-p-dioxins (PCDDs) in rats. Journal of Animal Science. 80:2461-2475.