<http://schema.org/query-input>
"required name=search_term_string"^^<http://www.w3.org/2001/XMLSchema#string>
<http://koopplein.nl/nederland/4694019/futbal-nogomet-f%C3%BAtbol-fotbal-b%C3%B3ng-%C4%91%C3%A1-fotboll.html>