The Red Laws Book is produced by the World Bridge Federation. The English Bridge Union publish it in England. 

It's revised every ten years and the 2017 version is now up for sale, and you can buy it at www.ebu.co.uk. I am told the edition presently being sold has an errata slip inserted in it. It might be worth waiting for a new edition.

In the past you could purchase a yellow book called Bridge Rules Simplified from Mr Bridge. It's not available at the moment, but it's possible that it's being revised in line with the new edition of the laws.