10th edition of 2012 and 11th edition of 2014
There is an even newer edition published, but I do not have it. In the same time I can compare two previous editions to look for their differences. After that I can conclude what can we expect from the 12th edition and is it worth buying if you have an older edition.
This is a good textbook for learning critical thinking. It can be used as a sole source of information of with a number or other books and courses.