Moore, David S.
W.H. Freeman, 1979
Buku Teks
Moore, David S.
WH. Freeman and Company, 2000
Multimedia
Michael S. Lewis-Beck, editor
Sage Publications, 1993
Buku Referensi
David, H.A.
John Wiley & Sons, 1981
Buku Teks
John Wiley and Sons, Inc., 1967
Buku Teks