The World Bank, 1997
Buku Teks
Open University Press, 1998
Buku Teks
Edited, Suzanne Ferriss, Mallory Young
Routledge, 2006
Buku Teks
Talitha Sal Shabilla, author
2018
UI - Skripsi (Membership)
Alexander, Linda Lewis, author
Jones & Bartlett Learning, 2014
Buku Teks