Dy, N. D., L. D. Luong, N. V. Tao, T. T. Thanh Ha, N. T. T. Anh, and N. M. Cuong. “Gelasian Stage and Expected Stratigraphical Units Having Similar Ages in Viet Nam”. Vietnam Journal of Earth Sciences, vol. 36, no. 1, June 2015, pp. 90-93, doi:10.15625/0866-7187/36/1/4146.