Ritchie, J.B., author
West Publshing Company, 1980
Buku Teks
Grimshaw, Austin
McGraw-Hill, 1960
Buku Teks
edited by M. David Ermann and Richard J. Lundman
Oxford University Press, 1978
Buku Teks
Gennifer Furst, editor
SAGE , 2009
Buku Teks
Edited by Michael Huemer
Routledge, 2002
Buku Teks