S, S., Edahwati, L., Wahyudi, M. R. A. . and Rahmah, N. A. (2024) “Optimization of Nano-Hydroxyapatite Production from Limestone with Effect of Gelatin Concentration and pH in Sol-Gel Synthesis”, International Journal of Eco-Innovation in Science and Engineering (IJEISE), 5(2), pp. 42–49. doi: 10.33005/ijeise.v5i2.137.