I have books that do not show up in the iOS app.
Not all books are licensed for mobile apps. Have you checked the product page?
it says:
"Runs on Windows, Mac and mobile."
Check here on the product pages for the books you are missing. Not all books are mobile enabled, although the majority are.
EDIT: I see MJ has answered and you have already checked. How long ago did you purchase them? Sometimes it takes a short while before they show up.
I checked each resource and could not find anything other than a link back to the collection and the collection says:
Strange that they are not showing up for you. I checked my library and have two of these volumes. They both show up on my iPad.Hopefully someone who knows more than me may be able to help yousolve the mystery😊
Try entering the command "rebuild index" (no quotes and lower case) into the reference box on the homepage.
You won't get any indication of anything happening apart from - hopefully - the sync circle spinning - but leave it a few minutes and see if it fixes the problem.
thanks for the tip
follow the rebuild index instructions and the rest of your collection will show