The 2021 PDF version of "Mecánica Clásica" by John R. Taylor is an excellent resource for anyone studying classical mechanics. Its comprehensive coverage, clear explanations, and extensive problem sets make it an ideal textbook for undergraduate and graduate students, as well as researchers. While some readers may prefer a physical copy, the digital version offers many advantages, including search functionality, digital bookmarking, and annotation capabilities. Overall, I highly recommend this PDF version to anyone seeking a thorough understanding of classical mechanics.