RE: XML Schema book recommendation?

I found another title, Priscilla Walmsley's book, Definitive XML Schema,
which has very good ratings on amazon.com.  

> Has anybody read the O'Reilly book on XML Schema by Eric van der Vlist? I
haven't seen any reviews yet. I am interested in any opinions about this
book.
> Are there other books anybody would strongly recommend on XML Schema?

Stuart Zakon
Objects by Design
http://www.objectsbydesign.com