See
SourceSystem.
I think mutual references without explanations explaining the differences are a waste of time, & disk space. If someone has an explanation of
SystemOfOrigin, please erase my entry here & put in your explanation. Also, if in the course of doing that you also reference
SystemOfReference, then you will have accomplished a great service to those like me who are trying to understand these concepts.
TerryLeeMoore 27 Jun 02