Put that query in a select (eg. ejbSelectDistinctIsbn) method, not a finder, and it should work.
Thanks for the suggestion. However, my understanding is that Select methods cannot be used within clients.
Perhaps, I could create a select method and use it within the bean to get a Collection of isbn.
Yep, that's exactly right. Expose another method in your CMP bean that will call the ejbSelect and return a Collection as a result.