Meier, Richard L.
The Massachusett Institute of Technology, 1974
Buku Teks
Dowton, Paul F.
Springer , 2009
Buku Teks
by Catherine Bauer [and others]; edited by Coleman Woodbury
The University of Chicago Press, 1953
Buku Teks
Amin, Ash
Polity Press, 2010
Buku Teks
Stevenson, Deborah
Open University Press, 2003
Buku Teks