Black, C.E.
Twentieth Century Europa: a history
Alfred A. Knopf, 1961
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Black, C.E.
Twentieth Century Europe: a history
Alfred A. Knopf, 1966
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Nichols, Jeannette P.
Twentieth century United States : a history
D. Appleton-Century, 1943
 Buku Teks
Teed, Peter
A dictionary of twentieth century history 1914-1990
Oxford University Press , 1992
 Buku Referensi
Readings in twentieth-century European history
edited by Alexander Baltzly, A. William Salomone
Appleton-Century-Crofts, 1950
 Buku Teks SO