Bowley, Arthur, author
Macdonald and Evans, 1951
Buku Teks
Johnson, Robert, author
PWS-Kent, 1984
Buku Teks
Bowley, Arthur, author
Staples Press, 1948
Buku Teks
Freund, John E., author
Pearson Education, 2007
Multimedia
Freund, John E., author
Prentice-Hall, 1980
Buku Teks