Ba, V., Thien, B.N., Truong, T.T.X., Dao, N.Q., Thuyen, L.X., Hao, L.C. and Loan, T.T.H. 2021. A preliminary study of geological variation of in-situ gamma dose rate in the vicinity of coal-fired power plants. Science and Technology Development Journal. 23, 4 (Jan. 2021), 815-822. DOI:https://doi.org/https://doi.org/10.32508/stdj.v23i4.2461.