Pender, Steven: Managing incomplete knowledge – Why risk management is not sufficient, in: International Journal of Project Management, Vol. 19 (2001), pp. 79-87.
Pender basically looks into the question if project risks is better described by the term ‚incomplete knowledge‘ and therefore be linked to probability theory. (Kudos to everyone who did the PMP and still knows which contingency reserve accounts for ‚known unknowns‘ and which for ‚unknown unknowns‘.)
He looks into the question of randomness (probability vs. non-probability), repeatability, human limitations to understand such a complex thing as a project, uncertainty & ignorance, flow of knowledge, and fuzziness of parameters.