Butters, J. Keith
Harvard University Press , 1951
Buku Teks
Smith, Dan Throop
National Bureau of Economic Research Inc. , 1949
Buku Teks
Smith, Dan Throop
Boston Harvard University 1952,
Buku Teks
Schwarz, Stephen
West Publishing, 1994
Buku Teks
Gaughan, Patrick A., author
John Wiley & Sons, 2002
Buku Teks