Chen, J., Zhang, Z., Ren, L., Liu, Y., & Liang, P. (2012). Effect of the Different COD/N Ratios on Multilevel Anaerobic/oxic Step-Feed Process for Integrated Removal of Carbon, Nitrogen and Phosphorus. Asian Journal of Chemistry, 25(2), 1098–1102. https://doi.org/10.14233/ajchem.2013.13713