Webb, J. W., & Reis, R. A. (1999). Programmable logic controllers: : principles and applications (4th ed.). Upper Saddle River: Prentice-Hall.
Παραπομπή Chicago StyleWebb, John W., and Ronald A. Reis. Programmable Logic Controllers: : Principles and Applications. 4th ed. Upper Saddle River: Prentice-Hall, 1999.
Παραπομπή MLAWebb, John W., and Ronald A. Reis. Programmable Logic Controllers: : Principles and Applications. 4th ed. Upper Saddle River: Prentice-Hall, 1999.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.