Graphic problems in petroleum geology / by L. W. Le Roy and Julian W. Low. LeRoy, L. W. (Leslie Walter), Low, Julian W. (Julian William), joint author. Petroleum Geology. TN870 .L38 553.282 LEG Includes bibliography. New York : Harper, C1954. C1954. 1954 Text ix, 238 p. : eng Harper's geoscience series