Williamson, Oliver E., author
Prentice-Hall, 1970
Buku Teks
Stone, Christopher D.
Harper & Row , 1975
Buku Teks
Miles, Robert H.
Goodyear Publishing Company, 1980
Buku Teks
Edwards, Ronald S., author
Macmillan, 1961
Buku Teks
Baumol, William J., author
Macmillan, 1959
Buku Klasik