E. David Ford, author
Cambridge University Press, 2000
eBooks
Carey, Stephen S.
Thomson Wadsworth, 2004
Buku Teks
Ackoff, Russell Lincoln, 1919-, author
John Wiley & Sons, 1962
Buku Teks
Earnshaw, Rae A., author
Springer-Verlag, 1992
Buku Referensi
Himsworth, Harold
ITB Press, 1997
Buku Teks