1. ACI (American Concrete Institute). (2005). “Building code requirements for structural concrete and commentary.” ACI 318-05/ACI 381R-05 Farmington Hills MI.
2. Further research in reinforced concrete, and its application to ultimate load design;Baker A. L. L.;Proc. Inst. Civ. Eng.,1953
3. Flexural strength of prestressed concrete beams;Billet D. F.;ACI J. Proc.,1954
4. CEN (European Committee for Standardization). (2004). “Eurocode 2: Design of concrete structures. Part 1: general rules and rules for buildings.” EN 1992-1-1:2004 Comité Européen de Normalisation Brussels Belgium.
5. Hognestad E. (1951). “A study of combined bending and axial load in reinforced concrete member.” Bulletin 399 Univ. of Illinois Engineering Experiment Station.