How Did You Discover These Pocket Guides?

In this book, you also talk about the various pocket guides that were issued to soldiers and sailors at all over the world for different countries. How did you discover these pocket guides as a source of insight into this period? So the pocket guides are really quite fascinating documents, and I commend them to your listeners. There's a guide for almost every country you can imagine or every region you can imagine... And they range from Alaska to Japan.