Free book downloards.
1. Around 1972, federal agents visited the public libraries and convinced them to withdraw military manuals from circulation.
2. As you know, most US military manuals are useless, with the exception of like how to take down a Garand.
3. I put into storage a 1910 free book by a US Army Captain. Read it like 3 times. He translated the Japanese military manual of training for night fighting. It is worth a read. However, here is 510 pages of work by the US Army after WW2 on the night fighting.
https://archive.org/details/JapaneseNightCombat I am old. My fighting will not be done on the flat range on a sunny day. It will be at night.
4. There are multiple projects like the "open book project" openbookproject.net. One such project is to put every book ever in print that is not currently copyrighted. You can find the websites.
5. If you sign up for free courses at MIT/Harvard, you can get written materials.
6. Your public library, when open, is a member of an inter-library exchange program. Decades ago, I would get books from across the country by paying $1.
7. Today, the libraries are closed. I have purchased about 60 books for myself from Thriftbooks and amazon (all used) for some pennies on the dollar. I also sent about 300-400 used books to young relatives in the last two years, mostly beginning readers.
Example. The Structure of Scientific Revolutions is marked $25 plus tax and I got it for $4, delivered. And with a big order, some books are free. One of the 100 best science books written since WW2. Took a long time to digest. Now I am onto Dreamtigers by J. Borges, reputedly the best poet from Argentina. If purchased new, the price would have been insane.