One of the things that I have for survival is a good library of books. Few sets of encyclopedias: Science and Technology that covers everything from the chemicals in a leaf to cause it to fall off a tree when it gets to fall to building a nuclear bomb and a set that covers History so that I know what the heck happened in the past so I don't repeat stupid things. Then there are the many books on homesteading the way out great grand parents did it as well as new techniques for things so that I can review past and present and build what really works the best. And, the classics both fiction and non-fiction. If the internet goes down, books will be a very valuable asset.