4/5 stars

If your library doesn’t own Leithold’s book, request it via ILL. They will borrow a physical copy from another university. You can then scan the chapters you need.

However, the very traits that make a PDF “hot” (free, unauthorized, widely shared) also make it illegal in most jurisdictions. Copyright on Leithold’s works is typically held by publishers (like Harper & Row or later imprints) or his estate, and unauthorized distribution violates the Copyright Act of 1976 (17 U.S.C. § 106).