1. Nielsen, S.P., Easthope, C., Gosselink, P., Gutsze, K., Roele, J.: Using Domino Workflow, IBM, Poughkeepsie, NY (2000).
http://www.redbooks.ibm.com/redbooks/pdfs/sg245963.pdf
2. SAP Business Workflow.
https://archive.sap.com/documents/docs/DOC-31056
3. KissFlow.
https://kissflow.com/
4. IOnet workflow manager.
https://www.ionetsoftware.com/workflow
5. Hollingsworth, D.: The Workflow Reference Model (1995).
http://www.wfmc.org/docs/tc003v11.pdf