Novels:
* Main range: There are a few novels that prominently feature Donna, like "The Time Machine" by Steve Cole and "The Time Traveller's Wife" by James Goss. These feature Donna in her own stories, not simply cameos.
* Other ranges: Donna appears in some books in the "New Series Adventures" and "The Eleventh Doctor Adventures" lines, but not always in a major role.
Short stories:
* Donna appears in several short stories, particularly in anthologies like "The Time Machine" and "The Time Traveller's Wife".
Spin-offs:
* There's a Doctor Who spin-off novel called "Donna's Day" which is dedicated entirely to Donna and her adventures.
Overall:
* While not all Donna Noble stories are listed in official sources, she's a popular character in the extended Doctor Who universe, appearing in a significant number of novels and short stories.
* It's worth noting that some stories may feature Donna's brief appearance or mention her in passing, while others focus on her as a main character.
* The best way to find out which books feature Donna Noble is to consult online databases like the Doctor Who wiki or search for lists of novels featuring specific characters.
It's impossible to give an exact count without a comprehensive list, but it's safe to say there are a considerable number of Doctor Who books featuring Donna Noble.