Guides:

(1) Noe, D.C., Jochim, C.L., and Rogers, W.P. (1997). A Guide to Swelling Soils for Colorado Homebuyers and Homeowners, Special Publication 43, Colorado Geological Survey Department of Natural Resources. Call (303) 866-4762. See: http://dnr.state.co.us/geostore/default.aspx

(2) Freeman, T.J., Littlejohn, G.S. and Driscoll, R.M.C. (1994). Has your House got Cracks?; A Guide to Subsidence and Heave of Buildings on Clay, Thomas Telford Services Ltd, London, England. See: https://www.asce.org/bookstore/book.cfm?book=2722

(3) ASCE, American Society of Civil Engineers (1995). So Your Home is Built on Expansive Soils, ASCE, New York. See: https://www.asce.org/bookstore/book.cfm?book=3591