<http://schema.org/query-input>
"required name=search_term_string"^^<http://www.w3.org/2001/XMLSchema#string>
<http://cdon.se/b%c3%b6cker/80_years_of_zentralblatt_math%3a_80_footprints_of_distinguished_mathematicians_in_zentralblatt-14934765>