Howdy. I can think of a few.
For general survival ...Life After Doomsday
, by Bruce Clayton. Its focus on nuclear survival, but it does cover "worst case" scenario and long term survival.It's a Disaster!
, by Bill and Janet Liebsch. This book covers all the major types of disasters.The Guide to Self-Sufficiency
, by John Seymour. This guide is agricultural-focused and it helps one get as self-sufficient as possible.Tappan On Survival
, by Mel Tappan. This is classic guide to getting started with preparedness.Survival Guns
, by Mel Tappan. This is a large text that covers all facets of firearms for survival. Some of it is quite dated, but its still a good text.Nuclear War Survival Skills
, by Dr. Edward Teller is, as the name implies, focused on nuclear war survival, but it does address long term situations. Its also available free here
, by Andy James. This is another getting started guide that focuses on getting ready on a budget.
Regarding military manuals ...FM 21-76 US Army Survival Manual
The SAS Survival Handbook, by John Wiseman
Hope that helps with your research.