* He's a prolific artist: Shaun Tan has illustrated numerous books, both his own and those written by other authors.
* Some works are collaborations: He often collaborates with writers, sometimes on multiple editions of the same book.
* No centralized database: There's no official, comprehensive list of all his illustration work.
However, you can find a good overview of his illustrated books on his official website, ShaunTan.com. He has an extensive bibliography section showcasing many of his collaborations.
If you're interested in learning more about his specific work, it's best to consult his website or search for book lists featuring his illustrations.