Sampson, Anthony
Coronet Books, 1982
Buku Teks
Spero, Joan Edelman, author
Wadsworth, 2010
Buku Teks
Spero, Joan Edelman, author
Routledge , 1997
Buku Teks
Hodgson, John S., author
Prentice-Hall, 1983
Buku Teks
Marcus, Edward, author
Pitman, 1965
Buku Teks