Soo, C.-S., W.-S. Yap, W.-M. Hon, N. Ramli, U. K. Md Shah, and L.-Y. Phang. “Improvement of Hydrogen Yield by Ethanol Producing Escherichia Coli Recombinants in Acidic Condition”. Electronic Journal of Biotechnology, vol. 26, no. 1, Mar. 2017, https://www.ejbiotechnology.info/index.php/ejbiotechnology/article/view/2016.12.007.