P. GANORKAR, RAJESH, and V.S. JAMODE. “Synthesis of 1,1-Bis-{2-Hydroxy-3-[1´ -Phenyl H-5´ -Aryl-Pyrazolin-3&Acute; -Yl] -5-Methyl Phenyl} Methanes ”. Asian Journal of Chemistry, vol. 15, no. 1, Mar. 2010, pp. 475-8, https://asianpubs.org/index.php/ajchem/article/view/21610.