Pais, Abraham
Inward Bound : of matter and forces in the physical world
Clarendon Press , 1986
 Buku Teks SO
Black, C.E.
Twentieth Century Europe: a history
Alfred A. Knopf, 1966
 Buku Teks SO
Keylor, William R., 1944-
The twentieth-century world : an international history
Oxford University Press, 1996
 Buku Teks SO
Readings in twentieth-century European history
edited by Alexander Baltzly, A. William Salomone
Appleton-Century-Crofts, 1950
 Buku Teks SO
Readings in Twentieth-Century European History
edited by Alexander Baltzly
Appleton-Century-Crofts, Inc, 1950
 Buku Teks SO