Henderik Alex Proper Stijn Hoppenbrouwers Theo P. van der Weide A Fact-Oriented Approach to Activity Modeling. 666-675 2005 conf/otm/2005-1 OTM Workshops https://doi.org/10.1007/11575863_86 https://www.wikidata.org/entity/Q59676984 db/conf/otm/otm2005-1.html#ProperHW05