Benwell, George, and Stephen MacDonell. “Assessing the Graphical and Algorithmic Structure of Hierarchical Coloured Petri Net Models”. Australasian Journal of Information Systems 2, no. 1 (September 15, 1994). Accessed November 10, 2026. https://www.ajis.aaisnet.org/index.php/ajis/article/view/412.