Phan, T., A. Nguyen, and H. Nguyen. “Cloning and Expression of LTB in Escherichia Coli and Bacillus Subtilis”. Science and Technology Development Journal, Vol. 16, no. 1, Mar. 2013, pp. 13-22, doi:https://doi.org/10.32508/stdj.v16i1.1392.