Books, outside of proper context, contain no useful knowlege. They assume too much context and access which is not reasonable if the civilization changes signif

Books, outside of proper context, contain no useful knowlege. They assume too much context and access which is not reasonable if the civilization changes significantly. More realistic is having and supporting efforts like Open Source Ecology... i.e. having a network of people who have the knowledge and hope enough of them survive in a disaster scenario.