Baird, John W., author
McGraw-Hill, 1983
Buku Teks
Locker, Kitty O., author
McGraw-Hill/Irwin, 2000
Buku Teks
Treece, Marla, author
Allyn and Bacon, 1994
Buku Teks
May, John
McGraw-Hill , 1983
Buku Teks
Munter, Mary, author
Prentice-Hall, 1982
Buku Referensi