Conversation so far:
Who did the artwork for Dr. Seuss books?
Theodor Seuss Geisel is known for his work writing and illustrating more than 60 books under the pen name Doctor Seuss.
What did Theodor Seuss Geisel draw?
Geisel evidently enjoyed drawing architecturally elaborate objects.

Question: what books did he illustrate?
Self-contained rewrite: What books did Theodor Seuss Geisel illustrate?