Hoang, N. H., N. T. Hien, H. T. Thu Hien, and K. H. Thanh. “Cloning and Expression of Keratinase Genes in Escherichia Coli BL21(DE3) from Bacillus Species”. Academia Journal of Biology, vol. 35, no. 3se, Apr. 2014, pp. 51-57, doi:10.15625/0866-7160/v35n3se.3839.