Battaloglu, Rifat, et al. “Determination of Urinary Calcium and Magnesium Levels by Atomic Absorption Spectrophotometry in Hypertensive Patients”. Asian Journal of Chemistry, vol. 24, no. 6, Feb. 2012, pp. 2369-72, https://asianpubs.org/index.php/ajchem/article/view/9134.