TY - RPRT TI - Potentiometric surface of the upper Floridan aquifer in the St. Johns River Water Management District and vicinity, Florida, September 1998 AU - L. A. Bradner PY - 1999 DO - 10.3133/ofr99100 UR - https://pubs.usgs.gov/publication/ofr99100 ID - ofr99100 ER -