Kien, T., H. Dong, T. Nguyen, and T. Nguyen. “Application of Material Flow Analysis (MFA) for Estimating the Potential of Nitrogen Recirculation in Closed-Ecosystem Based Catfish Farming”. Science & Technology Development Journal - Science of The Earth & Environment, Vol. 5, no. SI1, Nov. 2021, pp. SI1-SI12, doi:https://doi.org/10.32508/stdjsee.v5iSI1.569.