US Soil Type Texture Triangle
Canadian Soil Type Texture Triangle
- United States Department of Agriculture (1987) USDA Textural Classification Study Guide. Edited by National Employee Development Staff Soil Conservation Service. 1987–762–417 edn. U.S. Government Printing Office.
- The Expert Committee on Soil Survey (1983) The Canada Soil Information System (CanSIS): Manual for describing soils in the field 1982 revised. Edited by J. H. Day. Ottawa, Ontario: Land Resource Research Institute.