Author
Geological Survey (U.S.)
13
McDowell, Robert C., 1935-
3
Nelson, Arthur E. 1922-
3
Virginia. Division of Mineral Resources
3
Peper, John D.
2
Burton, William C. 1952-
1
Epstein, Jack Burton, 1935-
1
Froelich, A. J. 1929-
1
Hackley, Paul C.
1
Horton, J. Wright
1
Kline, Stephen W.
1
Loudoun County (Va.). Department of Natural Resources
1
Lyttle, Peter T.
1
Nelson, Frances J.
1
Orndorff, Randall C.
1
Pavlides, Louis, 1921-
1
Wygant, Adam W.
1