What are the differences between the 3 books below? Are they all pretty much the same? I wanted the text that would serve well for independent study for General Physics I and II and with not just plug-and-chug problems. What is "extended" in that edition compared to the regular edition? In reading posts, I've heard that getting the 1st or 2nd edition would be good (I don't know if that refers to the text with Krane as the third author or the book with Walker as the third author.) Physics, 5th Edition by David Halliday, Robert Resnick, Kenneth S. Krane Volume 1 ISBN: 978-0-471-32057-9 Volume 2 ISBN: 978-0-471-40194-0 Fundamentals of Physics, 8th Edition, Regular Edition David Halliday, Robert Resnick, Jearl Walker ISBN: 978-0-470-04472-8 Fundamentals of Physics Extended, 8th Edition David Halliday, Robert Resnick, Jearl Walker ISBN: 978-0-471-75801-3 http://www.wiley.com/WileyCDA/Section/id-302475.html?query=David+Halliday"