Wikipedia has many useful things, but sometimes reading them can be even more interesting.
This one was about the name of Transylvania. I read it and found it rather interesting, not so much the names or how they came to be but the fact that wikipedia does not really check for broken links, the last reference is in fact a dummy site (reference 15)
I was able to find the information about Transylvania and the Saxons and the name they use in the book Balkan Nightmare by Ann Wittman and the same information is given that is found there.
So, websites are one thing that you can see how people view mistakes. Again, books can also be misleading but a bit of cross referencing never hurts!