Tawfiq Amin, S., F. Mohsin Hamid, and O. Abdullah Jassim. “Construction of a Selective Membrane Electrode for the Determination of Procaine Hydrochloride by Schiff Bases”. Journal of Education and Science (JES), vol. 26, no. 5, Dec. 2013, pp. 60-73, doi:10.33899/edusj.2013.163079.