Silitonga AG, Purwati AA, Rusilawati E, Sandria W. Peran Upah, Pengawasan, Semangat Kerja dan K3 Terhadap Peningkatan Produktivitas Karyawan PT. Mitra Unggul Pusaka. INVEST [Internet]. 2022Apr.22 [cited 2024May2];3(1):38-55. Available from: http://journal.al-matani.com/index.php/invest/article/view/238