Birrell, Robert
Longman Cheshire, 1987
Buku Teks
Gollerkeri, Gurucharan
Oxford University Press, 2016
eBooks
Plane, David A.
John Wiley & Sons, 1994
Buku Teks
Roberts, Stephen H.
Melbourne University Press, 1964
Buku Teks
Askar Muhammad
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 2022
UI - Tesis Membership