NAGHIPOUR, ALI, and S. ABBASI. “Synthesis and Characterization of N,N-Dimethylamino- N’,N"-Diarylamino Phosphine Oxides”. Asian Journal of Chemistry, vol. 19, no. 4, Mar. 2010, pp. 3119-24, https://asianpubs.org/index.php/ajchem/article/view/13434.