Ewing, Ethel E., author
Rand McNally & Company, 1962
Buku Teks
Glubb, John
Stein and Day , 1969
Buku Teks
Folomkina, S., author
Moscow State Publishing House
Buku Referensi
chosen and edited by Richard Aldington
Viking Press, 1946
Buku Teks
Azim A. Nanji, editor
Gale Research, 1996
Buku Referensi