Kennedy, James H.
Pierian Press, 1984
Buku Referensi
Haley, John Owen
Edward Elgar Publishing, 2016
Buku Teks
Leo Suryadinata
Institute of Southeast Asian Studies, 2003
Buku Referensi
Rahner, Karl
The Crossroad Publishing Company, 1981
Buku Referensi
Doyglas J. Davies
Berg, 2002
Buku Teks SO