Anderson, Martin
Hover Institution Press, 1978
Buku Teks
Dinitto, Diana M.
Prentice-Hall, 2000
Buku Teks
Dinitto, Diana M.
Pearson, 2012
Buku Teks
Gordon, Margaret S.
Columbia University Press, 1963
Buku Teks
Deakin, Nicholas
Harvester Wheatsheaf, 1994
Buku Teks