Sugiyanto, Mohammad Badaruddin, Herpratiwi, Slamet Untung, Sabarudin. “The Influence of Learning Motivation on the Learning Outcomes of Vocational Students at Lampung University ”. International Journal of Advanced Science and Technology, Vol. 29, no. 05, Apr. 2020, pp. 133 -40, http://sersc.org/journals/index.php/IJAST/article/view/8649.