Doan, N.P.N. and T. Ha, P. (2015) “Using 15N Isotope Technique for Study the Balance of Nitrogen Fertilizer in Young Rubber Tree -Hevea Brasilliencis”, International Journal of Sciences: Basic and Applied Research (IJSBAR), 24(5), pp. 325–330. Available at: https://www.gssrr.org/JournalOfBasicAndApplied/article/view/4837 (Accessed: 27 September 2025).