1. [1] Gary Dunning, Introduction to Programmable Logic Controllers [2 ed.] (2001).
2. [2] William Bolton, Programmable Logic Controllers (Elsevier, Burlington, USA, 2009)
3. [3] ABB, Overview of the IEC 61131 Standard
4. [4] Bruce Carter and Thomas R. Brown, Handbook of Operational Amplifier Applications (2001)
5. [5] Cozmin Cristoiu, Adrian Nicolescu, "New approach for forward kinematics modeling of industrial robots with closed kinematic chain", 2017