There is a list of free programming ebooks. And I have decided to create a similar list but for software testing books.
Alexander Todorov (Open source QA, Senior QA engineer at Red Hat):
There's a huge list of free books on the topic of software testing. This will definitely be my summer reading list. I hope you find it helpful.
To the extent possible under law, Sergey Bronnikov has waived all copyright and related or neighboring rights to this work.