[publisher not identified], [date of publication not identified]
Buku Teks
Melady, Thomas Patrick, author
Macmillan, 1961
Buku Teks
Asean -Ec Energy Management Training and Research Centre, 1993,
Buku Referensi
Hetherington, John, author
F.W. Cheshire, 1967
Buku Teks
Asia Pacific Economics Group
Jakarta Post, 1996
Buku Teks