Kailash C.Baral, editor
Routledge, 2009
Buku Teks
Samuel Totten, editor
Routledge, 2009
Buku Teks
Kennedy, Richard
Macmillan Publishing Co. Inc, 1982
Buku Teks
Edward Arnold, 1978
Buku Teks
Robert M. Hutchins, Mortimer J. Adler, editors in chief
Encyclopaedia Britannica, Inc., 1963
Buku Referensi