Irving, John
Ballantine books, 1974
Buku Teks
Melkias Hetharia, author
Universitas Indonesia, 1996
UI - Tesis (Membership)
Cornell University Press, 1950
Buku Teks
Maclennan, Hugh
Macmillan Co. , 1945
Buku Teks
Thomas, Hugh
Harper & Row, 1967.
Buku Teks