SADEGH, Hamidreza, et al. “ADSORPTION OF AMMONIUM IONS ONTO MULTI-WALLED CARBON NANOTUBES”. Studia Universitatis Babeș-Bolyai Chemia, vol. 62, no. 2, June 2017, pp. 233-45, doi:10.24193/subbchem.2017.2.18.