Anger, Arthur L.
John Wiley & Sons, 1972
Buku Teks
Wode, Henning
Gunter Narr , 1981
Buku Teks
edited by Roger Blench and Matthew Spriggs
Routledge , 1997-1999
Buku Teks
The World Publishing Co., 1951
Buku Referensi
Morris, I.
Macmillan and Co. Ltd., 1950
Buku Teks