1. Programmable controllers versus the relay;Clarke;Control and Instruments,1985
2. Programmable controllers, concept and application;Jones,1983
3. Programmable Controllers, Operation and Application;Warnock,1988
4. A microprocessor-based programmable controller;Brown;Automatic Control Theory and Application,1980
5. CRT terminal for programmable controller;Athani;Microprocessors and Microsystems,1984