International encyclopedia of the social sciences : social science quotation, volume 19
David L. Sills, Robert K. Merton, editors
MacMilan Publishing, 1991
 Buku Referensi
International encyclopedia of political science
SAGE Reference, 2011
 Buku Referensi
The social science encyclopedia
edited by Adam Kuper and Jessica Kuper
Routledge, 1996
 Buku Referensi
International encyclopedia of the social sciences : volume 13 & 14
edited by David L. Sills
Macmillan and The Free Press, 1968
 Buku Referensi
International encyclopedia of the social sciences : volume 11 & 12
edited by David L. Sills
Macmillan and The Free Press, 1968
 Buku Referensi