References
- Bogli, A. 1980. Karst hydrology and physical speleology, Berlin, Springer
- Lively, R. S. and E. C. Alexander, Jr. 1985. Karst and the Pleistocene history of the Upper Mississippi River Valley. In: Pleistocene Geology and Evolution of the Upper Mississippi Valley. Winona State University, Minnesota, 31-32
- Lucas, J. R., G. R. Hallberg, K. M. Chauff, M. R. Howes. 1978. Lithological analysis of the 1-2mm sand fraction. In: Standard procedures for evaluation of Quaternary materials in Iowa. ed. G. R. Hallberg. Iowa Geological Survey Technical Information Series 8, 109p
- Oh, Jongwoo. 1990a. Slope soil formation and its attributes in southwestern Wisconsin. The Journal of Regional Development,, 16, 31-49
- Oh, Jongwoo. 1990b. Soil Development in Loess of the Southwestern Wisconsin Driftless Area. Proceedings, The 11th Korean International Symposium (Geoscience Section). The Korean Federation of Science and Technology Societies. Seoul, Korea, 198