Edmonds, I.G
Bobbs-Merrill, 1973
Buku Teks
Cooper, Barry, author
University of Missouri Press, 2004
Buku Teks
Milne, R.S.
Federal Publications, 1977
Buku Teks
Abdul Razak Baginda, author
Asean Academic Press, 2003
Buku Teks
Archipelago Press, 2006
Buku Referensi