1. Frost penetration below highway and airfield pavements;ALDRICH;Highway Res. Board Bull,1956
2. A.S.A.E. (1985). ASAE standards 1985. Amer. Soc. Agric. Engrs., St. Joseph, MI.
3. A.S.T.M. (1985). Annual A.S.T.M. standards. Part 11, Bituminous materials, soils, skid resistance. Amer. Soc. for Testing and Materials, Philadelphia, PA.
4. AMERICAN SOCIETY OF AGRONOMY (1982). Determinants of soil loss tolerance. Amer. Soc. Agron. Publ. No. 45, Madison, WI, 153 pp.
5. Über die physikalishe Bodenuntersuchung und über die Plastizität der Tone;ATTERBERG;Int. Mitt. für Bodenkunde,1911