Mohammed Ridha Mahmmod Wajde, Laith, et al. “Utilization Iron Filings and Microwave Heating in Roughening the Surface of Smoothed Coarse Aggregates”. International Journal of Engineering & Technology, vol. 7, no. 4.20, Nov. 2018, pp. 395-8, https://doi.org/10.14419/ijet.v7i4.20.26145.