, often provides digital versions or companion materials for students. Google Books What the Book Covers
Instead of searching for "patched" files, head over to the . It is a non-profit digital library. They often have legitimate scans of older editions that are available for borrowing or download. It is safe, legal, and free.
I can explain cam profiles, gear trains, governors, or balancing of rotating masses — no patched PDF required. Just ask.
Theory of Machines by and J.K. Gupta is a standard textbook for mechanical engineering students.
Here is the breakdown of the great PDF hunt.