Ward, Richard, author
Prentice-Hall, 1965
Buku Teks
Richards, R. Malcolm, author
Scott, Foresman, 1984
Buku Teks
Penson, John B., author
Prentice-Hall, 1982
Buku Teks
Unger, Maurice A., author
Allyn and Bacon, 1969
Buku Teks
Dauten, Carl Anton, 1913-, author
Prentice-Hall, 1948
Buku Teks