U.S.D.A. Soil Survey Staff. 1951. SOIL SURVEY MA^fUAL. U.S. Department of Agriculture, Soil 

 Conservation Service, Washington, DC. Agriculture Handbook No. 18. 502 pp. 



U.S.D.A. Soil Survey Staff. 1975. SOIL TAXONOMY. A BASIC SYSTEM OF SOIL CLASSIFICA- 

 TION FOR MAKING AND INTERPRETING SOIL SURVEYS. U.S. Department of Agriculture, Soil 

 Conservation Service, Washington, DC. 754 pp. 



Veneman, P.L.M., M.J. Vepraskas, and J. Bouma. 1976. THE PHYSICAL SIGNIHCANCE OF SOIL 

 MOTTLING IN A WISCONSIN TOPOSEQUENCE. Geoderma 15: 103-1 18. 



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