Marshall, Geoffrey
Oxford University Press, 1957
Buku Teks
Australian Government Publishing Service , 1995
Buku Teks
Lumb, R.D.
Butterworth, 1974
Buku Teks
Dodd, Lawrence C., 1946-
Princenton University Press, 1976
Buku Teks
Laski, Harold J.
George Allen and Unwin, 1952
Buku Teks