Fletcher, George P., author
Oxford University Press, 2000
Buku Teks
Michele Lamont; Laurent Thevenot
Cambridge University Press, 2000
Buku Teks
Edited by John J. Poggie and Robert N. Lynch
Greenwood Press, 1974
Buku Teks
Krugman, Paul R., author
Massachusetts Institute of Technoloy, 1994
Buku Teks
David Parker, Miri Song, editor
Pluto Press, 2001
Buku Teks