I. P. Y. . Laksana, N. N. . Yuliantini, N. K. . Suciani, I. P. Y. . Purandina, and G. P. . Boyce, “Employing e-portfolio based learning in improving self-efficacy of student’s speaking ability ”, JASL, vol. 5, no. 2, pp. 229–236, Dec. 2021.