“Potentiometric Analysis of Samarium Ion in Aqueous Solution Employing Selective Electrode Based on Crown Ethers - Samarium Picrate Complexes in a PVC Membrane”, IHJPAS, vol. 19, no. 3, pp. 117–133A, Dec. 2017, Accessed: May 13, 2024. [Online]. Available: https://jih.uobaghdad.edu.iq/index.php/j/article/view/1653