Hoan, H. V., P. Q. Nhân, Đặng Đức Nhận, F. LARSEN, W. FRANK, R. PURTSCHERT, and C. GERBER. “Hydrological Characteristics of Groundwater in the Nam Dinh Area from Isotopic Results”. Vietnam Journal of Earth Sciences, vol. 35, no. 2, Feb. 2014, pp. 120-9, doi:10.15625/0866-7187/35/2/3655.