Antti Pakonen Teemu Mätäsniemi Jussi Lahtinen Tommi Karhela A toolset for model checking of PLC software. 1-6 2013 ETFA https://doi.org/10.1109/ETFA.2013.6648065 conf/etfa/2013 db/conf/etfa/etfa2013.html#PakonenMLK13