So here's the results based on Whitespark for anyone intersted.
Exclusive confirmed relationships:
Localeze: YaSabe
Axciom: Local.com
Infogroup: Dexknows, Whitepages
Factual: none (on Whitespark diagram) but Apple does not appear to be listed (at least individually)
That all looks good if it is accurate.
Acxiom is a lot easier to track because SO MANY of their partners post "Data by Acxiom" in the footer. In fact, you could look at their inbound links via majestic or ahrefs and probably find a ton.
Localeze has the same thing to an extent I believe as Acxiom. You might be able to reverse engineer them as well.
Whitepages, 411.com (and there is another) are all the same people. And they are fed by ExpressUpdate exclusively (besides Yext) last time I checked. Also, the last time I checked so was Citysearch exclusively but you should double check that.
For Factual, I don't think I would use Apple Maps. Apple Maps is fed by a few different sources I believe, the least of which is Yelp, who I think is their major provider. You could always tell if the listing was Yelp or not but 9/10 all listings, unless self published, are going to come from Yelp. I would try to to find a different site maybe. Maybe not.
Without knowing your goals, I think maybe the best idea would be to look up a couple of businesses on each database and find an independent record. Either a listing that one has that none of the others have OR a unique listing where maybe ExpressUpdate uses a different formatting of a name than the others do. You could then do a search in Google for that.
What are you looking to learn in all this by the way? Publishing times?