1. American Petroleum Institute. 1974.API recommended practice for planning, designing, and constructing fixed offshore platforms, 5th ed., 31Dallas, Tex.: American Petroleum Institute. Recommended Practice 2A
2. American Society for Testing and Materials. 1974.Annual book of ASTM standards, pt. 19, 462Philadelphia: American Society for Test Materials.
3. Anderson, D. G. and Herrmann, H. G. 1971.Seafloor foundations: analysis of case histories, U.S. Naval Civil Eng. Lab. Tech. Rept. R‐731 83
4. Andresen, A., Sollie, S. and Richards, A. F. N.G.I. gas‐operated, sea‐floor sampler. Proc. 6th Conf. Soil Mech. Found. Eng. Montreal. vol. 1, pp.8–11.