A. Shrestha, S. Neupane, and L. Aryal, “Un-Plasticized Polyvinyl Chloride and its Growth on Nepalese Market”, Jnl Innov. Engin. Educ., vol. 3, no. 1, pp. 29–41, Mar. 2020, doi: 10.3126/jiee.v3i1.34322.