Thakur, B.G. “Synthesis, Spectral and Thermal Studies of Praseodymium(III) and Samarium(III) Complexes With N,N?,N?-Tri(2,4- dihydroxybenzophenone)triaminotriethylamine”. Asian Journal of Chemistry, vol. 20, no. 6, Mar. 2010, pp. 4952-4, https://asianpubs.org/index.php/ajchem/article/view/19128.