Blum, Walter J., author
University of Chicago Press, 1953
Buku Teks
Vickrey, William, author
Ronald Press, 1947
Buku Teks
Williamson, J. Peter (John Peter), author
Scott, Foresman, 1968
Buku Teks
Nightingale, Kath, author
Prentice-Hall, 2002
Buku Teks
edited by Emile Woolf
Pitman, 1986
Buku Teks