1. Amundson, R. 2004. Soil Formation. Chap. 5.01, in: Holland, H.D., Turekian, K.K. (Eds in Chief), Treatise on Geochemistry. Elsevier Press, Amsterdam, pp. 1–35.
2. Soil diversity and land use in the United States;Amundson;Ecosystems,2003
3. Preliminary bedrock geologic map of a portion of the Wilmington 30- by 60-minute quadrangle, southeastern Pennsylvania;Blackmer,2005
4. Bulk density. Methods of soil analysis. Part 1;Blake,1986
5. Uses and management of poultry litter;Bolan;Worlds Poult. Sci. J.,2010