<https://www.sportscollectorsdaily.com/notes-topps-deal-update-big-herbert-card-sold-psas-nscc-numbers-jersey-auctions-more/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.sportscollectorsdaily.com/tag/2021-national-sports-collectors-convention/>