SYAHPUTRA, Benny Tri; NASUTION, Muhammad Arifin. Pengaruh Pelatihan, Penerapan Standar Operasional Prosedur (SOP), Sistem Penghargaan dan Lingkungan Kerja Fisik Terhadap Produktivitas Kapster/Barber (Studi pada J&K Barber Shop Medan). Regress: Journal of Economics & Management, [S. l.], v. 1, n. 3, p. 117–128, 2022. DOI: 10.57251/reg.v1i3.259. Disponível em: https://jurnal.medanresourcecenter.org/index.php/REG/article/view/259. Acesso em: 11 mar. 2026.