AFRIANI, F.; J, E.; ZAITUN; TIANDHO, Y. Improvement of Hardness of Hydroxyapatite by the Addition of Silica from Tin Tailings. Journal of Engineering and Scientific Research, [S. l.], v. 2, n. 2, p. 85–89, 2020. DOI: 10.23960/jesr.v2i2.48. Disponível em: https://jesr.eng.unila.ac.id/index.php/ojs/article/view/48. Acesso em: 26 jun. 2022.