Berg, D. W., & Watts, G. M. (1967). Variations in groin design. U.S. Army Engineer Coastal Engineering Research Center, Dept. of the Army, Corps of Engineers.

Berg, Dennis W., and George M. Watts. Variations in Groin Design. [Washington, D.C.]: U.S. Army Engineer Coastal Engineering Research Center, Dept. of the Army, Corps of Engineers, 1967.

Berg, Dennis W., and George M. Watts. Variations in Groin Design. U.S. Army Engineer Coastal Engineering Research Center, Dept. of the Army, Corps of Engineers, 1967.