M. Nigam, S. Tyagi, M. Tiwari, M. Bhushan, A. Choudhary, and M. Gupta, “Esthetic Design”, J Orofac Res, vol. 5, no. 4, pp. 130–133, Jan. 1970, Accessed: Dec. 05, 2025. [Online]. Available: https://www.mansapublishers.com/jofr/article/view/2064