Zhang, S.; Peng, H.; Mu, D.; Zhao, H.; Hu, J. Simultaneous Determination Of (N-Ethyl Perfluorooctanesulfonamido Ethanol)-Based Phosphate Diester And Triester And Their Biotransformation To Perfluorooctanesulfonate In Freshwater Sediments. Environ Pollut 2018, 234, 821-829.