TY - RPRT TI - A regional assessment of chemicals of concern in surface waters of four Midwestern United States national parks AU - Sarah M. Elliott AU - David VanderMeulen PY - 2017 DO - 10.1016/j.scitotenv.2016.11.114 UR - https://pubs.usgs.gov/publication/70180975 ID - 70180975 ER -