<http://schema.org/query-input>
"required name=search_term_string"^^<http://www.w3.org/2001/XMLSchema#string>
<https://mobile.audible.com/pd/Self-Development/HypnoBirthing-Experience-Insiders-Guide-to-Safe-Healthy-and-Easier-Childbirth-Audiobook/B00IOTW8GI>