chaplinreview.com/
Book series offering in-depth analysis and research on Charles Chaplin, his films, his times and his influence. Contributors include many of the world's leading authorities on Chaplin and early film comedy.

2ndstorylaughter.com/index%202.htm
Fan site featuring famous comedians of the 20th century (this site was created by a middle school student!)

busterkeaton.com/
One of the most comprehensive Keaton fan sites ever.

en.wikipedia.org/wiki/Bert_Williams
Bert Williams was a pioneering black mime artist and variety entertainer, who created the first all-black musical on Broadway and also became a star of the Ziegfeld Follies.

"The Comedy of Charlie Chaplin - Artistry in Motion" by Dan Kamin