Artikel Jurnal
Gold, Joseph
International Monetary Fund , 1983
Buku Teks
Myers, Robert G., author
Prepared for the Educational Research Review and Advisory Group, 1980
Buku Teks
Darul Aqsha, author
INIS, 1995
Buku Referensi
edited by Egbert Jahn
St Martin's Press, 1978
Buku Teks