"Mastering Quantum Mechanics" has become a go-to resource for students and researchers alike due to its:
Some websites may offer free PDF downloads of Zwiebach's textbook, but these sources are often unofficial and may not be authorized by the author or publisher. We advise against using these sources, as they may pose risks such as:
(to help decide if it’s worth buying):
: The textbook is directly based on Prof. Zwiebach’s lecture notes for the MIT course series 8.04, 8.05, and 8.06. You can download the full set of lecture notes as PDFs for free on the MIT OCW Quantum Physics I page MITx Online / edX