Keylor, William R., 1944-
The twentieth-century world : an international history
Oxford University Press, 1996
 Buku Teks SO
Twentieth-century building materials : history and conservation / edited by Thomas C. Jester
McGraw-Hill, 1995
 Buku Teks SO
Black, C.E.
Twentieth Century Europa: a history
Alfred A. Knopf, 1961
 Buku Teks SO
Black, C.E.
Twentieth Century Europe: a history
Alfred A. Knopf, 1966
 Buku Teks SO
Teed, Peter
A dictionary of twentieth century history 1914-1990
Oxford University Press , 1992
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