Angus and Robertson, 1957
Buku Teks SO
compiled by E.G. Withycombe
Clarendom Press, 1950
Buku Referensi
Gabriele vom Bruck; Barbara Bodenhorn
Cambridge University Press, 2006
Buku Teks
Oxford University Press, 1990
Buku Referensi
M. Gugah Patria
Fakultas Ekonomi dan Bisnis Universitas Indonesia, 1993
UI - Skripsi Membership