<http://schema.org/query-input>
"required name=search_term_string"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.audible.de/pd/English-Mysteries-Thrillers/Agatha-Raisin-and-the-Fairies-of-Fryfam-Hoerbuch/B008OZSSDE>