Leung, Hau Y., and Ramapillai V. Balendran. “Resonant Frequency in Polypropylene Fibre Reinforced Concrete (PFRC) With Pozzolanic Materials”. Journal of Civil Engineering and Management 8, no. 3 (September 30, 2002): 169-176. Accessed November 15, 2024. https://jest.vgtu.lt/index.php/JCEM/article/view/9119.