Robbins, Lionel
The economist in the twentieth century and the other lectures in political economy
Macmillan, 1954
 Buku Teks
Australian conservatism : essays in twentieth century political history
editor, Cameron Hazlehurst
Australian National University Press, 1979
 Buku Teks
The Routledge dictionary of twentieth-century political thinkers
edited by Robert Benewick and Philip Green
Routledge , 1992
 Buku Teks SO
Kuper, Leo
Genocide: its political use in the twentieth century / Leo Kuper
Vale University Press , 1982
 Buku Teks
Schapiro, J. Salwyn
The world in crisis : political and social movement in the twentieth century / J. Salwyn Schapiro
McGraw-Hill, 1950
 Buku Teks