R. . Jaidee, S. . Kongpetch, A. Prawan, L. . Senggunprai, U. . Kukongviriyapan, and V. . Kukongviriyapan, “Quercetin Enhances Phenformin in Inhibition of Cholangiocarcinoma Cell Growth”, SRIMEDJ, vol. 35, no. 3, pp. 249–254, May 2020.