Carrow, R. S. (1998). Soft logic a guide to using a PC as a programable logic controller (First edition.). McGraw-Hill.

Carrow, Robert S. Soft Logic a Guide to Using a PC as a Programable Logic Controller. First edition. New York: McGraw-Hill, 1998.

Carrow, Robert S. Soft Logic a Guide to Using a PC as a Programable Logic Controller. First edition. McGraw-Hill, 1998.