Hi can you be more specific about which tags you are referring to? I checked those tags but all of them have some books. I didn't find any tag in EE with nothing listed.
Some of these links are actually other products (not books) on Amazon. We remove these products. Still need to improve the UI so sparse lists look nicer. Thank you for pointing that out!
No problem. I'm sure each category can be endlessly fleshed out. It just looked weird that there was a lot of EE not covered.