1. Bouma, A. L.; Van Riel, A. C.; Van Koten, H.; Beranek W. J. 1961: Investigations on models of eleven cylindrical shells made of reinforced and prestressed concrete, Proceedings of the symposium on shell research, Delft, North-Holland, Amsterdam, 79?101
2. Ngo D.; Scordelis A. C. 1967: Finite element analysis of reinforced concrete beams, ACI Journal, 64: 152?163
3. Kupfer H.; Hilsdorf H. K.; Rüsch H. 1669: Behavior of concrete under biaxial stresses. ACI Journal, 66: 656?666
4. LiuT. C. Y.; Nilson A. H.; Slate F. O. 1972: Biaxial stress-strain relations for concrete. Journal of the structural division, ASCE, 98: 1025?1034
5. Deutscher Ausschuß für Stahlbeton, Heft 229;H. Kupfer,1973