1. B. Baldwin, 1949 . A Preliminary Report on the Sioux Quartzite. South Dakota Geological Survey Report of Investigations No. 63.
2. California Computer Products, Inc., 1971 . A General Purpose Contouring Program, Users Manual . Anaheim, California. 96 pp.
3. GRAVITY EXPLORATION FOR GROUNDWATER AND BEDROCK TOPOGRAPHY IN GLACIATED AREAS
4. M. B. Dobrin, 1976 . Introduction to Geophysical Prospecting . Third Edition . McGraw-Hill, New York. 630 pp.
5. THE GRAVIMETER IN STUDIES OF BURIED VALLEYS