Bhagwati, Jagdish
Penguin Books, 1969
Buku Teks
Folsom, Ralph Haughwout
[publisher not identified], [date of publication not identified]
Buku Teks
The National Bank, 1979
Buku Teks
National Australia, 1990
Buku Teks
Marasinghe, Lakshman
Butterworth Asia, 1998
Buku Teks