Zhu, Jinhua, et al. “Analysis of Bisbenzylisoquinoline Alkaloids by Micellar Electrokinetic Chromatography With Large Volume Sample Stacking Technology”. Asian Journal of Chemistry, vol. 24, no. 8, Apr. 2012, pp. 3671-4, https://asianpubs.org/index.php/ajchem/article/view/9419.