Hey all, deciding which book to get for Immuno. 'The Immune System' 3rd Edition by Parham is the required one, and is highly rated on Amazon, but the 4th Edition is also out. It (4th) only has 7 reviews, which are mostly scattered. I already have Sompayrac's 'How the Immune System Works,' and like it, just looking for a more in depth reference. Any opinions on 3rd vs 4th Edition?