Niu, D., C. Li, P. Wang, L. Huang, N. Peace Mchunu, S. Singh, B. A. Prior, and X. Ye. “Twin-Arginine Signal Peptide of Bacillus Licheniformis GlmU Efficiently Mediated Secretory Expression of Protein Glutaminase”. Electronic Journal of Biotechnology, vol. 42, Nov. 2019, https://www.ejbiotechnology.info/index.php/ejbiotechnology/article/view/2019.10.006.