автор: Richard L. Morrill

Stanley D. Brunn is professor of geography at the University of Kentucky. Gerald R. Webster is professor of geography at the University of Wyoming. Richard L. Morrill is professor emeritus of geography at the University of Washington. Fred M. Shelley is professor of geography at the University of Oklahoma. Stephen J. Lavin was professor of geography at the University of Nebraska, Lincoln. J. Clark Archer is professor of geography at the University of Nebraska, Lincoln.