Petrography : an introduction to the study of rocks in thin sections / by Howel Williams, Francis J. Turner, and Charles M. Gilbert. Williams, Howel, 1898-1980. Turner, Francis J., author. Gilbert, Charles M., 1910-, author. Petrology. QE431 .W73 552 WIP Includes bibliographical references and index. San Francisco : W.H. Freeman, 1954. 1954. 1954 Text x, 406 p. : eng A Series of geology texts Series of geology texts.