Quantum Mechanics by Gupta, Kumar, and Sharma is a popular, comprehensive textbook in India covering fundamental and advanced topics like Schrodinger’s equation, angular momentum, and relativistic quantum mechanics for physics students. It is known for its detailed, structured approach to both non-relativistic and relativistic theory.
The truly updated editions (post-2020) are rarely available for free legally. They cost anywhere from ₹350 to ₹600 ($4–$7 USD). quantum mechanics book by gupta kumar sharma free updated