Whitworth, Michael H.
Wiley-Blackwell, 2010
Buku Teks
Ayers, David
Blackwell Publishing, 2008
Buku Teks
Forrest-Thomson, Veronica
Manchester University Press, 1978
Buku Teks
Robinson, Alan
Macmillan, 1988
Buku Teks
Dembo, L.S.
University of California Press, 1966
Buku Teks