Pratiwi, Dian, and Widiyanto Widiyanto. “PENGARUH FAKTOR INTERNAL DAN FAKTOR EKSTERNAL TERHADAP PRODUKTIVITAS KERJA”. Economic Education Analysis Journal 7, no. 2 (January 20, 2019): 654-670. Accessed May 5, 2024. https://journal.unnes.ac.id/sju/eeaj/article/view/28282.