<http://schema.org/alternateName>
"The Portal"^^<http://www.w3.org/2001/XMLSchema#string>
<https://texashistory.unt.edu/explore/collections/USTOPO/browse/?start=40&fq=str_title_serial%3ADigital+US+Topo+Maps%3A+7.5+Minute+Series+(Topographic)>