Certain Books are "Hidden" in the marketplace?

I'm browsing the DND beyond marketplace and noticed that there are books that don't appear under any categories (Rules, Adventures or Campaign Settings), such as the Pugilist Class and Heroes of Faerun. Even when I search through the site's list of all books they don't appear. The only way I managed to find them was to search them specifically by name.

Not sure if this is intentional or if there's another way to find books on the marketplace I'm not aware of. Those were the only two I noticed but I'm worried I may be missing out on other books I'd have to know by name since they don't appear any other way.