S, H. A., R. Cortes-Martinez, and R. Alfaro-Cuevas-Villanueva. “Fluoride Removal from Aqueous Solutions by Mechanically Modified Guava Seeds”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 11, no. 1, Dec. 2013, pp. 159-72, https://gssrr.org/index.php/JournalOfBasicAndApplied/article/view/1326.