Frank, Robert H., author
McGraw-Hill, 2001
Buku Teks
Mankiw, N. Gregory, author
Harcourt College, 2001
Buku Teks
Fairchild, Fred Rogers, author
Macmillan, 1954
Buku Teks
Benham, Frederic, author
Pitman, 1947
Buku Klasik
Blodgett, Ralp H., author
Rinehart & Company, 1951
Buku Teks