P. Kunapongkiti, P. Pornkulwat, T. Limpiyakorn, P. Homyok, P. Nayramitsattha, and C. Rongsayamanont, “Persistence of Nitrite-Oxidizing Bacteria in Entrapped Cell-Based Partial Nitrifying Reactor Treating Ammonia-Rich Wastewater”, Eng. J., vol. 23, no. 2, pp. 1–10, Mar. 2019, doi: 10.4186/ej.2019.23.2.1.