Pound, Roscoe, author
Transaction Publishers, 1999
Buku Teks
Feldman, Fred
McGraw-Hill, 1986
Buku Teks
Runkle, Gerald.
Holt, Rinehart and Winston, 1985
Buku Teks
Vreede, Frans, author
Oxford University Press, 1953
Buku Teks
Bortolotti, Lisa, author
Polity Press, 2008
Buku Teks