Jeison, D., I. Díaz, and J. B. van Lier. “Anaerobic Membrane Bioreactors: Are Membranes Really Necessary?”. Electronic Journal of Biotechnology, vol. 11, no. 4, Oct. 2008, pp. 0-0, https://www.ejbiotechnology.info/index.php/ejbiotechnology/article/view/v11n4-9.