Pham, X., O. Huynh, and H. Phan. “A Survey of the Fluctuation of Microorganisms in Process of Manufacturing Oolong Tea”. VNUHCM Journal of Science and Technology Development, Vol. 17, no. 2, June 2014, pp. 52-59, doi:https://doi.org/10.32508/stdj.v17i2.1359.