McColvin, Eric
Longmans, Green and Co., 1946
Buku Teks SO
Muhammad Taufani
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2017
UI - Skripsi Membership
R. Siti Hajar Amali
2018
UI - Tesis Membership
Pease, Martha Redding
Fourth Estate, 1984
Buku Referensi
Ilana Tan
Gramedia Pustaka Utama, 2010
Buku Teks SO