If you already know the basics and want to focus on differentiating Keynesian and Austrian, I would recommend studying the history of economics as a whole instead of focusing on basic textbooks. Individual textbooks, especially in the social sciences, are heavily dependent upon the historical perspective of the editors and authors compiling the book. It is easier to start progressing into the specific perspectives (Keynesian, etc) by actually studying the authors who started them, then move on to modern interpretations and progress afterwards.
So what I'm saying is go read Keynes and Hayek themselves.
So what I'm saying is go read Keynes and Hayek themselves.