Routledge, 2015
Buku Teks
Blois, Lukas de, author
Routledge, 1997
Buku Teks
Brown, A.J., author
George Allen and Unwin, 1959
Buku Teks
Brown, A.J., author
George Allen and Unwin, 1959
Buku Klasik
Mortimer J. Adler, editor in chief
Encyclopedia Britanica, 1994
Buku Referensi