Vigo Dewangga. The Perception of Computer Engineering Department Students at Politeknik Negeri Jember towards the Use of Duolingo in Learning English. SELL [Internet]. 2020 Feb. 28 [cited 2025 May 4];5(1):32-9. Available from: http://publikasi.stkippgri-bkl.ac.id/index.php/SL/article/view/243