Hand, D.J., author
John Wiley & Sons, 1981
Buku Teks
Fredman, Sandra, author
Oxford University Press, 2011
Buku Teks
edited by Craig Donnellan
Independence Educational, 1995
Buku Teks
Rom, Raphael
Berlin Springer-Verlag , 1990
Buku Teks
Krutilla, John V., author
Johns Hopkins University Press, 1958
Buku Teks