Greenlees, Ian
Longman Group, 1971
Buku Teks
Lindeman, Ralph D
Twayne Publishing, 1965
Buku Teks
[Canberra] Angus & Robertson 1989,
Buku Referensi
Greenlees, Duncan
The Theosophical Publishing House, 1952
Buku Teks
Norman, Donald A, author
Basic Book, 2004
Buku Teks