Burnley, I. H., author
McGraw-Hill, 1976
Buku Teks
Hendeson, Ronald F.
Institute of Applied Economic and Social Research University of Melbourne, 1970
Buku Teks
Princeton University Press, 1944
Buku Teks
Blainey, Geoffrey, 1930-, author
Sun Books, 1980
Buku Teks
Lamberton, D.M.
Tudor Press, 1970
Buku Teks