Dror, Yehezkel
Elsevier, 1978
Buku Teks SO
Krone, robert M.
John Wiley & Sons, 1980
Buku Teks
Howlett, Michael
Oxford University Press, 2009
Buku Teks
Weimer, David L.
Prentice-Hall, 1992
Buku Teks
Weimer, David L.
Pearson Prentice Hall, 1989
Buku Teks