/* For each book found at both bn.com and amazon.com, list the title of the book and its price from each source. */ FOR $a_book IN document("RainbowCore/Kweelt/XMP/prices.xml")//book[ source/text() = "www.amazon.com" ], $b_book IN document("RainbowCore/Kweelt/XMP/prices.xml")//book[ source/text() = "www.bn.com" ][ title = $a_book/title ] RETURN $b_book/title, $a_book/price/text(), $b_book/price/text()