Fought, Carmen, author
Cambridge University Press, 2006
Buku Teks
Beard, Adrian, author
Routledge, 2004
Buku Teks
Potter, Simeon, author
Penguin Books, 1979
Buku Teks
Hoff, Erika, 1951-, author
Wadsworth, 2005
Buku Teks
Gerber, Philip L., author
Wadsworth , 1968
Buku Teks