Links
Background of the REA (Resource, Event, Agent) model which this software is based on:
McCarthy's original 1982 REA paper
Extending REA from internal business systems into larger economic networks:
Radically Distributed Supply Chain Systems
A semantic model for Internet supply chain collaboration a little dated and most of the internal links are broken, but still useful
ISO Accounting and Economic Ontology based on REA
Here's the ISO REA diagram: