Rauzatam Mardiah
Politeknik Negeri Medan, 2017
Artikel Jurnal
Taylor, Jim
American Management Association;, 2011
eBooks
Bleeke, Nancy
[American Management Association, ], 2013
eBooks
Rexa Egyastara Cipta
2016
UI - Tugas Akhir
Stinnett, Bill
Elex Media Komputindo, 2005
Buku Teks