Sadeghi, Mohammad, and Nahid Ghasemi. “Syntheses and Swelling Kinetics Study of Gelatin-G-poly(acrylamide-Co-2-Acrylamido-2-Methyl Propane Sulfonic Acid) Superabsorbent Hydrogel With Salt-Sensitivity Properties”. Asian Journal of Chemistry, vol. 24, no. 5, Jan. 2012, pp. 2049-53, https://asianpubs.org/index.php/ajchem/article/view/8931.