His scientific writings for lay people are amazing(World of Carbon comes to mind). He could string everything together so well.
Single mother of two (her husband didn't want to take care of their children and left her alone) she could write a book in less than a week ¡!
https://en.m.wikipedia.org/wiki/Andre_Norton
Met someone connected with ACE books back in the 1960s and they said she wrote so many books and under so many different guises that she didn't even know about everything she'd produced.
This NYT article is cited as the source: http://archive.ph/glW3U
12 years later, I wonder how computer generated books are now.
For very prolific authors, I wonder how much of their work is genuinely great and how much is just rephrasing something they'd written earlier or just uninteresting. I'm not sure I have enough time to read any to find out!