Simple enough for students, comprehensive enough to serve as a reference for professionals. Subjects include formalism and its interpretation, an analysis of simple systems, symmetries and invariance, methods of approximation, elements of relativistic quantum mechanics, much more. "Strongly recommended." — American Journal of Physics.
Here's a sample of other books in this Dover category
Quantum Theory of Many-Particle Systems by Alexander L. Fetter, John Dirk Walecka Self-contained treatment of nonrelativistic many-particle systems discusses both formalism and applications in terms of ground-state (zero-temperature) formalism, finite-temperature formalism, canonical transformations, and applications to physical systems. 1971 edition.