1. AASHTO T307. (2007). Determining the resilient modulus of soils and aggregate materials. Washington, DC: American Association of State Highway and Transportation Officials.
2. Bennert, T. & Maher, A. (2005).The development of a performance specification for granular base and subbase material(Report FHWA-NJ-2005-003). New Jersey, NJ: Department of Transportation, pp. 55.