PanAmerican Conference on Soil Mechanics and Foundation Engineering (14th : Puerto Rico) & American Society of Civil Engineers. Soil Mechanics and Foundations Division. (1971). Proceedings of the 4th PanAmerican conference on soil mechanics and foundation engineering, Puerto Rico, 1971. American Society of Civil Engineers.
Lua i Stíl Chicago (17ú heag.)PanAmerican Conference on Soil Mechanics and Foundation Engineering (14th : Puerto Rico) agus American Society of Civil Engineers. Soil Mechanics and Foundations Division. Proceedings of the 4th PanAmerican Conference on Soil Mechanics and Foundation Engineering, Puerto Rico, 1971. New York: American Society of Civil Engineers, 1971.
Lua MLA (8ú heag.)PanAmerican Conference on Soil Mechanics and Foundation Engineering (14th : Puerto Rico) agus American Society of Civil Engineers. Soil Mechanics and Foundations Division. Proceedings of the 4th PanAmerican Conference on Soil Mechanics and Foundation Engineering, Puerto Rico, 1971. American Society of Civil Engineers, 1971.