Gandolfo, Giancarlo
Springer-Verlag , 2016
eBooks
Sachs, Jeffrey D.
Harvester Wheatsheaf, 1993
Buku Teks SO
Parkin, Michael, 1939-
Prentice-Hall, c1992
Buku Referensi
Morley, Samuel A.
The Dryden Press, 1984
Buku Teks
Samuelson, Paul Anthony, 1915-2009
New York, 2005
Buku Teks