Horton, Gray W.
Business Books , 1969
Buku Teks
Rockport Publishers, INC, 1995
Buku Teks SO
Marcella Stefania Yunitasari
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2023
UI - Skripsi Membership
Shakina Amri Ghiffara
Universitas Indonesia, 2017
UI - Skripsi Membership
edited by Martin M. Pegler
Retail Reporting Corporation, 1989
Buku Referensi