1. Achenbach J. D. (1973). Wave propagation in elastic solids . North-Holland Press Amsterdam 310–318.
2. “ASTM standard test method for compressive strength of cylindrical concrete specimens.” (1996a). C 39-94 American Society for Materials and Testing West Conshohocken Pa.
3. “ASTM standard test method for pulse velocity through concrete.” (1996b). C 597-83 American Society for Materials and Testing West Conshohocken Pa.
4. Bungey J. H. and Millard S. G. (1996). Testing of concrete in structures 3rd Ed. Blackie Academic & Professional Publishing London 52.