1. J.D. Allison, and D.S. Brown , 1992 . MINTEQA2: A Geochemical Assessment Model for Environmental Systems. Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency. Athens, Georgia.
2. R.H. DeBruin, R.M. Lyman, R.W. Jones, and L.W. Cook , 2000 . Coalbed Methane in Wyoming. Information Pamphlet No. 7, Wyoming State Geological Survey, Laramie, Wyoming.
3. ESTIMATION OF ACTIVITY COEFFICIENTS FROM THE ELECTRICAL CONDUCTIVITY OF NATURAL AQUATIC SYSTEMS AND SOIL EXTRACTS
4. B. Hanson, S.R. Grattan, and A. Fulton , 1993 . Agricultural Salinity and Drainage: A Handbook for Water Managers. University of California Irrigation Program, University of California, Davis, California.