21
by Stoessinger, John G.
Published 1993
22
Published 1992
23
by Macridis, Roy C.
Published 1972
24
by Jones, Walter S.
Published 1985
25
Published 1985
26
by Marshall, Peter
Published 1997
27
by Rosecrance, Richard N.
Published 1963
28
by Kegley, Charles W.
Published 1997
29
by Beloff, Max, 1913-
Published 1955
30
Published 2003
31
by Keylor, William R, 1944-
Published 1992
32
33
by Larsen, Henrik
Published 1998
34
Published 1984
35
by Gupta, M. G.
Published 1986
36
Published 1990
37
by Holsti, K. J, 1935-
Published 1972
38
by Haskins, Caryl P.
Published 1964
39
by Burns, Alan, Sir, 1887-
Published 1957
40
by Herring, Eric
Published 1995