Belmonte, M., Hsieh, C.-F., Figueroa, C., Campos, J. L., & Vidal, G. (2011). Effect of free ammonia nitrogen on the methanogenic activity of swine wastewater. Electronic Journal of Biotechnology, 14(3). Retrieved from https://preprints.pucv.cl/index.php/ejbiotechnology/article/view/v14n3-11