Our modern stone age / Robert L. Bates, Julia A. Jackson. Bates, Robert Latimer, 1912- Jackson, Julia A., 1939- Nonmetallic minerals. TN799.5 .B37 1982 553.6 BAO Includes index. Includes bibliographical references and index. Los Altos, Calif. : W. Kaufmann, c1982. c1982. 1982 Text vii, 132 p. : eng