Simai, Mihály
Global power structure, technology and world economy in the late twentieth century
Pinter Publishers , 1990
 Buku Teks
Revolutions of the late twentieth century
edited by Jack A. Goldstone, Ted Robert Gurr, Farrokh Moshiri
Westview Press, 1991
 Buku Teks SO
Keylor, William R., 1944-
The twentieth-century world
Oxford University Press, 1996
 Buku Teks
Ewen, David
The world of twentieth-century music
Prentice Hall, 1968
 Buku Referensi
Snyder, Louis L.
World in the twentieth century
Princeton University Press, 1964
 Buku Teks SO