1. American Association of State Highway Officials (AASHTO). (1994). LRFD specifications for highway bridges 1st Ed. AASHTO Washington D.C.
2. American Association of State Highway Officials (AASHTO). (1996). Standard specifications for highway bridges 16th Ed. AASHTO Washington D.C.
3. Boussinesq M. J. (1876). “Theoretical essay on the equilibrium of elasticity of pulverulent masses and on the pressure of earths without cohesion.” Memoires Couronnes Acad. R. Sci. Belg. 40(4).
4. Burmister D. M. (1943). “The theory of stresses and displacements in layered systems and applications to the design of airport runways.” Proc. Highway Research Board Washington D.C. 23 127–148.
5. Gerber E. (1929). Discussion of investigations of the distribution of pressure in locally loaded sand A.-G. Gebr. Leemann Zurich.