Details regarding data sources?

[rbelew]

I am looking for details curious regarding the "provenance" the various data
sources, and looking for your help in documenting just what these
details are.

I find this statement on your
main page

DATA SOURCES: This list includes a complete list of all sources
ever used in the data set, since January 21, 2010. Some sources
listed here (e.g. ECDC, US CDC, BNO News) are not currently relied
upon as a source of data.

Where, please, could I find additional documentation, concerning for
example:

- which are the *current* sources?
- when were you retrieving from these sources?
- what exactly is done by your *aggregation* methods across
  multiple sources?