While discussing this article, someone recommended the https://www.ufo-search.com project as a datasource to integrate.

I had a look at it and, looking at their code, just realized it is itself an aggregation project of many sources .

The funny thing is that it aggregates my own rr0 web site :) so If I'd aggregate it, I may theoretically loop integrating myself integrating ufo-search integrating myself... forever (but in real life, it is easy to filter out some sources from it). You may wonder why they attempted to integrate a non-english databases like rr0 or Overmeire... and it looks that they have automated the english-to-french translation!

That's another -massive- example of database integration, and it seems to work great.... aside the fact that they don't merge and so have a number of duplicates.