Your ship is sinking. What’s the one medical resource you’d save?

Which one medical information resource would you take with you to the desert island?
Put another way, what is your most valued medical resource?
Australian Doctor’s How to Treat (conflict declared) is great, and is essential reading, but it’s about how to treat, less about how to access services.
It’s great for how to treat rheumatoid arthritis, but not designed to help find a rheumatology outpatient clinic in your area. (Good luck!)