Easton, David.The Political System.New York: Knopf, 1953.
2.
Haas, Ernst B."Regionalism, Functionalism, and Universal International Organization,"World Politics, 8, 2 ( Jan. 1956), 238-63
3.
. —. "The Comparative Study of the United Nations,"World Politics , 12, 2 (Jan. 1960), 298-322.
4.
—. Beyond the Nation-State.Stanford, Calif.: Stanford University Press, 1964.
5.
Hall, A.D., and R.E. Fagen."Definitions of a System,"General Systems, 1(1956), 18-28
6.
. Hanrieder, Wolfram F."Actor Objectives and International Systems,"Journal of Politics, 27, 1(Feb. 1965), 109-32
7.
. Hoffmann, Stanley H.Contemporary Theory in International Relations.Englewood Cliffs, N.J.: Prentice-Hall, 1960 .
8.
—. "International Systems and International Law,"World Politics , 14, 1( Oct. 1961), 205-37
9.
. Kaplan, Morton.System and Process in International Politics.New York : Wiley, 1957.
10.
Liska, George.Nations in Alliance. Baltimore, Md.: Johns Hopkins Press, 1962.
11.
Masters, Roger."A Multi-Bloc Model of the International System,"American Political Science Review, 55, 4(Dec. 1961), 780-98
12.
. Osgood, Robert E."Stabilizing the Military Environment,"American Political Science Review, 55, 1(Mar. 1961), 24-39
13.
. —. Nato: The Entangling Alliance.Chicago : University of Chicago Press, 1962.
14.
Rosecrance, Richard N.Action and Reaction in World Politics.Boston: Little, Brown, 1963.
15.
Rosenau, James N."The Functioning of International Systems,"Background , 7, 3(Nov. 1963a), 111-17
16.
. —. Calculated Control as a Unifying Concept in the Study of International Politics and Foreign Policy. Research Monograph No. 15. Princeton, N.J.: Center of International Studies, Princeton University , 1963b.
17.
— (ed.). International Aspects of Civil Strife.Princeton, N.J.: Princeton University Press, 1964.
18.
Russett, Bruce M."Toward a Model of Competitive International Politics,"Journal of Politics, 25, 2 (May 1963), 226-47
19.
. Singer, J. David."The Level-of-Analysis Problem in International Relations,"World Politics, 14, 1(Oct. 1961), 77-92.