Mobley, Herbert L. and R.C. Brinlee. Soil Survey of Comanche County, Oklahoma. Neher, R.E. 1984. Soil survey of Sierra County Area, New Mexico. C.S. Holzhey, K.W. Flach, and B.R. Brasher.
Soil scientists proficiency in describing soil consistence.
Nettleton, W.D., K.W. Flach, and G. Borst. A toposequence of soils in tonalite grus in the southern California Peninsular Range. Soil Survey Invest. O'Neil, A.M. 1952 . A key for evaluating soil permeability by means of certain field clues.