Annisa, T., A. Azkiya, R. Fauzi, A. Nandiyanto, and S. Hofifah. “Cost Analysis and Economic Evaluation for Manufacturing Hydroxyapatite Nanoparticles from Eggshell Waste”. International Journal of Research and Applied Technology (INJURATECH), Vol. 1, no. 1, June 2021, pp. 211-26, doi:10.34010/injuratech.v1i1.5669.