Zhai, Qing-Zhou, and Xiao-Xia Zhang. “Spectrophotometric Determination of Hemoglobin With Lanthanum(III)-(DBC-Arsenazo)”. Asian Journal of Chemistry, vol. 20, no. 7, Mar. 2010, pp. 5060-6, https://asianpubs.org/index.php/ajchem/article/view/12935.