And remind your audience of the difference between yours, ours, and hers. After all, they want to hear what you have to say, not what we have to say. Not if the only source in the entry's bibliography is Baker's book. And likely not if it's one of only two citations and the entry is short and of an esoteric topic - one that requires special research and therefore couldn't be commonly known. The world wide web compounds the problem.
Web sites can cite web sites.
Often the cited sites don't cite their sources. Even if they do, they can repeat the incestuous citation practices outlined above. In the past, something was common knowledge if it appeared in three or more sources that did not cite each other. Now the minimum seems to be five independent sources that do not cite each other. There are some exceptions to this practice.