Menard, Kevin P.
CRC Press, Taylor & Francis Group, 2008
Buku Teks SO
Siregar, Riduan Akbar
2015
UI - Tesis Membership
Woods, Robert L.
Prentice-Hall, 1997
Buku Teks SO
Jeary, Alan
E & FN Spon, 1997
Buku Referensi
Klee, Harold
CRC Press, 2011
Buku Teks SO