1. Chlorites and hydroxy interlayered vermiculite and smectite;Barnhisel,1989
2. Geomorphic history of the Kickapoo region, Wisconsin;Bates;Geol. Soc. Am. Bull.,1939
3. Soil Chemistry;Bohn,1985
4. The Nature and Properties of Soils;Brady,1974
5. Handbook for Soil Thin Section Description;Bullock,1985