Staley, Eugene, author
McGraw-hill, 1965
Buku Teks
Bruch, Mathias, author
Westview Press, 1984
Buku Teks
Keith, Lyman A., author
McGraw-Hill, 1975
Buku Teks
Vernon, Raymond, author
Harvard University Press, 1972
Buku Teks
Crabbe, Ernest H., author
South-Western Publishing, 1961
Buku Teks