Ali K. AL-asadi , Abdul Razzaq A. Shaheen, Waleed Kh. Hadi,. “EXPERIMENTAL STUDY ON REINFORCED CONCRETE BEAMS WITH HYBRID STEEL- POLYPROPYLENE FIBERS”. Design Engineering (July 7, 2021): 1916- 1927. Accessed May 5, 2024. http://thedesignengineering.com/index.php/DE/article/view/2517.