61
by Parkinson, C. Northcote, 1909-
Published 1958
62
63
by Lipson, Charles
Published 1985
64
by Haug, Hans, 1921-
Published 1993
65
Published 1987
66
by Hunt, R. N. Carew
Published 1950
67
by Heibroner, Robert L.
Published 1953
68
by Modelski, George
Published 1988
69
by Apter, David E, 1924-
Published 1993
70
by Mohamad Faisol Keling
Published 2006
71
by Humphrey, John P, 1905-
Published 1984
72
Published 1995
73
by James, Alan, 1933-
Published 1990
74
75
by Grantham, Dewey M.
Published 1963
76
Published 2003
77
78
by Gray, Colin S, 1943-
Published 1992
79
80