Norman, Colin, author
Worldwatch Institute, 1980
Buku Teks
Millman, Jacob, author
McGraw-Hill, 1987
Buku Teks
e Home Entertainment, Inc, 2011
Buku Referensi
United Nations Departemen of Public Information, 1990
Buku Teks
Edited, Dorojatun Kuntjoro-Jakti; Keiji Omura
Institute of Developing Economies, 1995
Buku Teks