I loved Modern Quantum Mechanics by Sakurai, where Quantum Mechanics is presented and worked out. Now I would like to proceed further, and learn about Relativistic Quantum Mechanics and Quantum Field Theory. I started by reading Sakurai's Advanced Quantum Mechanics, but later I found that the theory is much more than what is presented on that book. So, I did some searches on web, and I ended up with the following recommended books: - 3 volumes on QFT by Weinberg; - QFT by Peskin, Schroesder; - QFT by Schwartz. What book out of these three would be the best one? Or, for those who know Sakurai's Advanced QM, would it be better for me that those three above? Or, if there's still other good ones which I did not mention, please let me know. Thanks.