<http://schema.org/query-input>
"required name=search_term"^^<http://www.w3.org/2001/XMLSchema#string>
<https://store.kobobooks.com/en-us/ebook/the-best-of-henry-drummond-the-greatest-thing-in-the-world-eternal-life-beautiful-thoughts-natural-law-in-the-spiritual-world-and-more>