Davis, James Cushman, author
Baca, 2005
Buku Teks
Bauer, Susan Wise, author
Elex Media Komputindo, 2012
Buku Teks
Maisels, Charles Keith
Routledge, 1999
Buku Teks
Livingstone, R. W.
Clarendion, 1951
Buku Teks
Hodges, Henry, author
Penguin Press, 1970
Buku Teks