What is a process model composed of?

Greta Adamo, Chiara Ghidini, Chiara Di Francescomarino. What is a process model composed of?. Software and Systems Modeling, 20(4):1215-1243, 2021. [doi]

@article{AdamoGF21,
  title = {What is a process model composed of?},
  author = {Greta Adamo and Chiara Ghidini and Chiara Di Francescomarino},
  year = {2021},
  doi = {10.1007/s10270-020-00847-w},
  url = {https://doi.org/10.1007/s10270-020-00847-w},
  researchr = {https://researchr.org/publication/AdamoGF21},
  cites = {0},
  citedby = {0},
  journal = {Software and Systems Modeling},
  volume = {20},
  number = {4},
  pages = {1215-1243},
}