Haber, Audrey
Addison-Wesley, 1973
Buku Teks SO
McClave, James T.
Prentice-Hall, 2000
Buku Teks
McClave, James T.
Dellen Publishing, 1979
Buku Teks
Hays, William Lee, 1926-1995
Harcourt Brace Colege, 1994
Buku Teks
McClave, James T.
Dellen Publishing, 1985
Buku Teks