Mckinlay, Brian, author
Drummond, 1979
Buku Teks
with introduction by Harold Earl Hammond
Cambridge Book, 1964
Buku Teks
New South Wales University Press, 1984
Buku Teks
Welch, David, author
Heinemann, 1994
Buku Teks
Powell, Fred Wilbur
Brookings Institution, 1939
Buku Teks