., I. I., A. Herius, D. Saputra, and A. M. Fadi. “Analysis of The Effect Of The Addition of Fly Ash and Petrsoil on The Soil Shear Strength of The Swamp Area”. Indonesian Journal of Environmental Management and Sustainability, vol. 4, no. 1, Mar. 2020, pp. 10-13, doi:10.26554/ijems.2020.4.1.10-13.