Choi, S.K., K.M. Bang, J.H. Song, D.H. Lee, I.S. Kim, D.I. Jung, and J.T. Hahn. “Synthesis of 1,5,3,7-Diazadiphosphocine-1,5-Dicarboxylic Acids and Their Esterifications”. Asian Journal of Chemistry 22, no. 4 (March 30, 2010): 3094–3100. Accessed July 23, 2024. https://asianpubs.org/index.php/ajchem/article/view/11518.