TY - RPRT TI - Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, September 2006 AU - Sandra L. Kinnaman AU - Joann F. Dixon PY - 2007 DO - 10.3133/ofr20071215 UR - https://pubs.usgs.gov/publication/ofr20071215 ID - ofr20071215 ER -