This one is written by a married couple that traveled the world and collected sourdough starters.
Classic Sourdough by Ed Wood and Jean Wood
It is an amazing history and travel guide, if you are into that kind of stuff.
I found it has some great recipes and most importantly, gave me some confidence is using, feeding, and vacationing sourdough starters. It is just not that feasible to keep all your starters active all the time in the home kitchen.
Currently, I have a New Zealand rye starter that stays in vacation mode until I need it. I bought it as a dry powdered starter and kept it in a dark drawer for a couple of years, afraid to activate it, because I don’t eat that much rye bread.
I also have a family hand me down sourdough starter that I use more often, sometimes several times a week, sometimes I go weeks keeping it dormant in the refrigerator.
This book gave me the confidence to keep and use these starters.