TY - RPRT TI - Potentiometric surface of the upper Floridan aquifer in the St. Johns River Water Management District and vicinity, Florida, May 2004 AU - Sandra L. Kinnaman AU - Leel Knowles PY - 2004 DO - 10.3133/ofr20041377 UR - https://pubs.usgs.gov/publication/ofr20041377 ID - ofr20041377 ER -