<http://schema.org/query-input>
"required name=search_term"^^<http://www.w3.org/2001/XMLSchema#string>
<https://store.kobobooks.com/ebook/memoirs-of-constant-the-emperor-napoleon-s-head-valet-containing-details-of-the-private-life-of-napoleon-his-family-and-his-court-3>