Mortensen, Kurt W., author
Serambi Ilmu Semesta, 2011
Buku Teks
Inkeles, Alex
Harvard University Press, 1962
Buku Teks
Hogan, Kevin, author
John Wiley & Sons, 2006
Buku Teks
edited by Andreas Bandak and Lars Hojer
John Wiley & Sons, 2015
Buku Teks
Tiscione, Kristen Konrad Robbins, author
WEST A Thomson Reuters business, 2009
Buku Teks