Ground water in southeastern Pennsylvania / by George M. Hall, with analyses by Margaret D. Foster and Charles S. Howard ; prepared in cooperation between the United States Geological Survey and the Pennsylvania Topographic and Geologic SurveyHall, George Martin, 1891-1941. · First published 1934Open the Tome
Ground water in southwestern Pennsylvania / by Arthur M. Piper, with analyses by Margaret D. Foster and C.S. Howard ; prepared in cooperation between the United States Geological Survey and the Pennsylvania Topographic and Geologic SurveyPiper, Arthur M. (Arthur Maine), 1898-1989. · First published 1933Open the Tome
