Winfred Jebaraj, J., et al. “Synthesis and Conformational Analysis of Some 3-Alkyl-2,6-Diarylpiperidin-4-One Semicarbazones”. Asian Journal of Chemistry, vol. 20, no. 7, Mar. 2010, pp. 5282-8, https://asianpubs.org/index.php/ajchem/article/view/12945.