Henderson, James W., author
South-Western, 2002
Buku Teks
edited by Peter C. Smith, Laura Ginnelly and Mark Sculpher
Open University Press, 2005
Buku Teks
Phelps, Charles E., author
Harper Collins, 1992
Buku Teks
Folland, Sherman, author
Prentice-Hall, 1997
Buku Teks
Folland, Sherman, author
Prentice-Hall, 2001
Buku Teks