Baron, Robert A.
Allyn and Bacon, 1987
Buku Teks
Baron, Robert A.
Allyn and Bacon, 1994
Buku Teks
Whitaker, Jerry C.
CRC Press , 1998
Buku Referensi
Morris, Charles G.
Prentice-Hall, 2003
Buku Teks
Feldman, Robert Stephen, 1947-
McGraw-Hill , 2005
Buku Teks SO