Amazon Product Advertising API - Show only "real" books, not Kindle or audiobooks

i'm requesting the API like this:

$params["Operation"] = "ItemSearch";
$params["SearchIndex"] = "Books";
$params["Author开发者_运维问答"] = "...";

This shows "real" books of course but also "Kindle Editions", audio books and audio cds.

Is there a way to filter "real" books out of this by request?

Or do i have to check every item in the xml-result manually? (if ItemAttributes/ProductGroup = Book then...)

Thanks!

I know this question is a little old, but here's my answer.

I've had good luck by using Amazon's "Power" attribute: &Power= binding = Hardcover or binding = paperback.

Just remember everything needs to be escaped so: &Power=%20binding%3A%20Hardcover%20%or20binding%3A%20paperback%20.