Sourcing my books… alternatives to Amazon

Given recent revelations about poor treatment of staff, you may wish to source your books from places other than Amazon. Here is a list suggested by the Guardian. You can find my books on most, but not all of them.
http://www.independent.co.uk/news/uk/avoiding-amazon-the-5-best-alternatives-to-the-online-bookseller-giants-10458698.html