Decisions and diplomacy : essay in twentieth--century International history
edited by Dick Richardson and Glyn Stone
Routledge, 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
 Buku Referensi
Nichols, Jeannette P.
Twentieth century United States : a history
D. Appleton-Century, 1943
 Buku Teks SO