Abbas, Ismail Ibrahim, Hassan Hasan Hammud, and Hasan Shamsaldeen. “Calix[4]pyrrole Macrocycle: Extraction of Fluoride Anions from Aqueous Media”. European Journal of Chemistry 3, no. 2 (June 30, 2012): 156–162. Accessed May 3, 2024. https://www.eurjchem.com/index.php/eurjchem/article/view/542.