Colander, David C., author
McGraw-Hill, 2004
Buku Teks
Phillips, Charles F., author
University of North Carolina , 1963
Buku Teks
Mundell, Robert A.
Macmillan, 1968
Buku Teks
Country Beautiful Foundation, 1966
Buku Teks
Simons, Robert, author
Upper Saddle River Prentice Hall 1999,
Buku Teks