1. Barber E. S. and Sawyer C. L. (1952). “Highway subdrainage.” Proc. Highway Research Board Washington D.C. 643–666.
2. Granular soils in rigid-wall permeameters: method for determining the degree of saturation
3. Chu T. Y. Davidson D. T. and Wickstrom A. E. (1955). “Permeability tests for sands.” Permeability of Soils ASTM Special Technical Publication No. 163 ASTM West Conshohocken Pa. 43–55.
4. Crovetti J. A. and Dempsey B. J. (1991). “Pavement subbases.” Final Rep. Proj. IHR - 525 Univ. of Illinois at Urbana-Champaign Urbana Ill.
5. Highlands K. L. and Hoffman G. L. (1988). “Subbase permeability and pavement performance.” Transp. Res. Rec. No. 1159 Transportation Research Board Washington D.C. 7–20.