Belgian Business Federation, 1974
Buku Teks
B. S. Chlepner
The Bookings Institution, 1943
Buku Teks
John Karlie, author
2014
UI - Tugas Akhir
Crabb, John H.
Fred B. Rothman and Company, 1982
Buku Teks
Juni Arina Khairiyati, author
2018
UI - Skripsi (Membership)