Watson, Tony J., author
Routledge, 1995
Buku Teks
Fox, Alan, author
Colier-Macmillan, 1973
Buku Teks
Watson, Tony J., author
Routledge, 1995
Buku Teks
Parker, S.R., author
George Allen and Unwin , 1975
Buku Teks
Miller, Delbert C.
Harper & Row, 1964
Buku Teks