by Wallace de Witt, Jr. Middle Eocene intrusive igneous rocks of the central Appalachian valley and ridge province-setting, chemistry, and implications for crustal structure / by C. Scott Southworth, Karen J. Gray, and John F. Sutter.
De Witt, Wallace, Jr., 1920-2012
Washington : U.S. G.P.O. ; Denver : For sale by Book and Open-File Report Sales, U.S. Geological Survey, 1992.