Amin, Ash
Polity Press, 2010
Buku Teks
Stevenson, Deborah
Open University Press, 2003
Buku Teks
Forman, Richard T. T.
Cambridge University Press, 2014
Buku Teks
by Catherine Bauer ... [et al.] ; edited by Coleman Woddbury
University of Chicago Press, 1953
Buku Teks
Choldin, Harvey M.
McGraw-Hill, 1985
Buku Teks