Kaplan, Jacob J.
The challenge of foreign aid policies, problems and possibilities
N.Y. Frederick A. Praeger , 1968
 Buku Teks
Lovel, John P
The challenge of American foreign policy/ John P. Lovell
Macmillan, 1985
 Buku Teks
Indian foreign policy : agenda for the 21st century
editorial board, Lalit Mansingh ... [and others]
Foreign Service Institute in association with Konark Publishers, 1998
 Buku Teks SO
World Investment Report 1999 foreign direct investment and the challenge of development
United Nations, 1999
 Buku Teks
Feinberg, Richard E.
The intemperate zone : the Third World challenge to U.S. foreign policy
W.W. Norton, 1983
 Buku Teks SO