Johnson, A. C., Aerni, H. R., Gerritsen, A., Gibert, M., Giger, W., Hylland, K., … Wettstein, F. E. (2005). Comparing steroid estrogen, and nonylphenol content across a range of European sewage plants with different treatment and management practices. Water Research, 39(1), 47-58. https://doi.org/10.1016/j.watres.2004.07.025