I certainly do not deny the problems mentioned by T, Kathie, and M, but I do question whether the Abraham Lincoln profile constitutes a good example. Both the profile and the Wikipedia article have humongous lists of sources and references. Unfortunately many of them on the profile are ancestry.com sources, but still, you could head off to your library with the list and a big notebook in hand and spend weeks researching this one notable.
If Dick is perhaps asking which items in the sources list support which facts, there is even quite a bit of that kind of association in the profile -- the sections on Ancestry, Descendants, and Timelines all point to specific sources for listed events. So in many cases I think the answer is there, and the solution to "how do I see them?" is click the link, or Google the title, or go to your library and ask the librarian for help if necessary.
What would you folks do differently with Abe's profile? How do you think the data should be presented, or should different data be presented?