by D. A. O'Keefe, Donald E. Kirby, Fun-Den Wang, J. E. Dooley, John M. Gomes, Karl C. Dean, L. C. Headley, Lester J. Crow, Noel N. Moebs, Richard A. Dick, Robert Lynn Crosby, Tedford C. Briggs, United States. Bureau of Mines. Staff, Coal Sampling and Inspection, Victor R. Spironello, C. I. Pierce, Donald H. Desy, Dwight E. Couch, Eben L. Singleton, H. Austin Tucker, Joseph W. Sterner, Kenji Uchida, Meng-Cherng Sun, Robert C. Bates, Ronald F. Kendall, Donald E. Hirsch, Morton Min Wong, Robert M. Doerr, Thomas A. Sullivan, W. K. Sawyer, William C. Hill

1969

by Donald E. Kirby, D. A. O'Keefe, Thomas A. Sullivan

1972

by Anthony J. Strazisar, D. E. Wolfson, Donald E. Kirby, E. M. Murphy, Edward George Davis, Frederick W. Leighton, James W. Vogh, R. A. Welsh, R. V. Higgins, Robert C. Ellman, A. W. Deurbrouck, Alan J. Leighton, D. A. O'Keefe, Ignatz L. Feld, J. O. Crabtree, Leroy Dockter, Richard Lincoln Stein, Wilbur I. Duvall, John W. Belter, Thomas A. Sullivan, Thomas F. Tomb

1972

by Anthony J. Strazisar, D. E. Wolfson, Donald E. Kirby, E. M. Murphy, Edward George Davis, Frederick W. Leighton, R. A. Welsh, R. V. Higgins, A. W. Deurbrouck, Alan J. Leighton, D. A. O'Keefe, Ignatz L. Feld, J. O. Crabtree, Richard Lincoln Stein, Wilbur I. Duvall, Thomas A. Sullivan, Thomas F. Tomb

1972