Acs, Zoltan J., author
Edward Elgar, 2002
Buku Teks
edited by Andrew Karvonen, Federico Cugurullo and Federico Caprotti
Routledge, Taylor & Francis Group, 2019
Buku Teks
Greenhalgh, Christine., author
Princeton University Press, 2009
Buku Teks
edited by F. Stuart Chapin and Shirley F. Weiss
John Wiley & Sons, 1962
Buku Teks
United Nations
United Nations, 1987
Buku Teks