Phat, Tran Huu, and Hoang Van Quyet. “Ripplon Modes of Two Segregated Bose-Einstein Condensates in Confined Geometry”. Communications in Physics 26, no. 1 (April 12, 2016): 11. Accessed October 24, 2021. https://vjs.ac.vn/index.php/cip/article/view/7790.