D. Nguyễn Văn, A. Vũ Thị Lan, and L. Hoàng Ngọc, “RESULTS OF MONITORING RADON (222Rn; 220Rn) GAS AND GAMMA DOSE RATE OVER TIME AT MUONG HUM RARE EARTH MINE, LAO CAI ”, SJ TTU, vol. 8, no. 2, Jul. 2022.