Ghorbani, Ali, et al. “Strength Characteristics of Cement-Rice Husk Ash Stabilised Sand-Clay Mixture Reinforced With Polypropylene Fibers”. The Baltic Journal of Road and Bridge Engineering, vol. 13, no. 4, Dec. 2018, pp. 447-74, https://doi.org/10.7250/bjrbe.2018-13.428.