Pang’ Raran, Josua Gilang, et al. “Pengaruh Penambahan Bubuk Gypsum Pada Tanah Lempung Dengan Pengujian Direct Shear”. Paulus Civil Engineering Journal, vol. 4, no. 1, Jan. 2024, pp. 53-60, https://doi.org/10.52722/4rf1pp03.