1. Altitude and configuration of the potentiometric surface in the Triassic sandstones and shales, northeastern Chester County, Pennsylvania, September 1987 through January 1988 Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Reston, Virginia : Department of the Interior, U.S. Geological Survey, 1989 Format: Map Access & Availability: Loading
2. Altitude of the potentiometric surface and changes in water levels in the Sparta-Memphis aquifer in eastern and southern Arkansas, spring 1986 Author/Creator: Geological Survey (U.S.), cartographer Publication/Creation: Little Rock, Arkansas : Department of the Interior, U.S. Geological Survey, 1989 Format: Map Access & Availability: Loading