Activity coefficientsDirectional Drilling for Coalbed DegasificationDavid M. Soboroff, Alexander May, Arthur B. Campbell, Bruce D. Hanson, C. B. Davison, David C. Oyler, Edward D. Thimons, H. R. Beard, Harold J. Heinen, Harold L. Rhodes, Ivan L. Nichols, James L. Holman, Jerry T. McLendon, Leroy H. Wullstein, Milton M. Tilman, Philip Thompson, Ralph H. Nafziger, Richard C. Repsher, Robert C. Gabler, Timothy J. Driscoll, United States. Bureau of Mines, Annie G. Smelley, Arlyn G. Lawrence, Bernard S. Covino, Bruce D. Sartwell, D. Jan Black, G. E. McClelland, H. Heystek, J. L. Huiatt, Jerry D. Troyer, Nancy S. Raymon, Philip E. Sanker, Robert Lynn Crosby, Robert P. Vinson, W. R. McDonald, Wallace W. Roepke, William P. Diamond, Andrew A. Cochran, Don C. Seidel, Fred N. Kissell, L. A. Neumeier, Murray Rosen, P. W. Jeran, Paul B. Needham, Roald Edmund Lindstrom