Sources

http://casebook.org/

Casebook is a site, dedicated to Jack the Ripper.If you read the “About” page of them, you will find that they are quite serious with their website and many of their facts can be found in other sources, too.

http://www.youtube.com/watch?v=i9Brtq4nLOM

This is a part of a documentary about the Ripper.It was made by historians and professors of this topic, so I think it would be quite reliable.

The movie “From Hell”

A stunning film, distributed  by 20th Century Fox.It made the historic facts suspenseful and lively.

http://en.wikipedia.org/wiki/Jack_the_ripper

Wikipedia is said to be a famous and reliable source, people share and if the entries are not correct, they are deleted.

http://www.jack-the-ripper-walk.co.uk

This is the official homepage of the walk.It is reliable because its made by the leaders and the company of the Tour.