1. Rogers J. J. W. and Adams J. A. S. Thorium and uranium. In Handbook of geochemistry Wedepohl K. E. ed. (Berlin, etc.: Springer, 1978, II-V, pt 90, 39 p. and pt 92, 50 p.
2. Nichols C. E. etal. Uranium geochemical survey in the Crystal City and Beeville quadrangles, Texas. Open File Rep. U.S. Dep. Energy GJBX-19(77), 1977, 326 p.
3. Nichols C. E. etal. Wide-spaced uranium geochemical survey in the Plainview, Lubbock, and Big Spring quadrangles, Texas. Open File Rep. U.S. Dep. Energy GJBX-73(78), Dec. 1977, 229 p.
4. Nichols C. E. etal. Hydrogeochemical and stream sediment pilot survey of Llano area, Texas. Open File Rep. U.S. Dep. Energy GJBX-36(76), 1976, 152 p.
5. Nichols C. E. etal. Northwest Texas pilot geochemical survey. Open File Rep. U.S. Dep. Energy GJBX-60(76), 1976, 227 p.