I don't know about most people but I prefer to have physical copies or coin and banknote books for reference. And while the Standard Catalog of World Banknotes is a great resource sometimes it leaves some to be desired. For a while I have been looking for a book that is specifically about Czechoslovakia, unfortunately a book like that simply doesn't exist in English. I have great resource for Latvian Banknotes by Lee Gordon. It is in English, readily available, and has large full color photos of notes as well as specimen and test sheets.
A few months ago through probably a few rabbit holes I discovered that a new book covering Czechoslovakian, Slovak, Czech, Bohemia and Moravia, and even earlier Austro-Hungarian notes had been published by Aurea Numismatika and Pavel Hejzlar in the Czech Republic. It was available through aukro.cz which is basically Czech eBay, and after finding a seller that shipped internationally and wiring money to them to pay for my book and waiting about 3 weeks it arrived.
Now from the beginning I knew that there would be a barrier between using this book to its fullest. I do know some Czech, not enough to hold a conversation but enough to read words here and there. I will say this is a fantastic book, it goes into great detail about individual notes. It includes pictures or varieties as well as the placement of specimen stamps and their rarities. The values are fairly accurate as the book is recently published.
Sometimes finding country specific books can be difficult but the hunt continues. All in all I am glad that I was able to find this resource and while it still isn't quite as useful as it could be it is a wonderful addition to my book collection.