Physics does not change. Newton’s laws were the same in 1687 and will be the same in 2087. The 6th and 7th editions of Fundamentals of Physics are considered "out of print" for digital distribution, but used physical copies sell for on AbeBooks, eBay, or Amazon Marketplace.
This article will explore everything you need to know: the history of the book, its structure, why the PDF is so sought after, the legal risks of downloading unauthorized copies, and—most importantly—the alternatives to getting a "Halliday Physik PDF." Halliday Physik Pdf