<https://melscameras.com/news/lenses/sigma-50mm-f1-4-dg-hsm-pricing-announced#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://melscameras.com/news/lenses/sigma-50mm-f1-4-dg-hsm-pricing-announced>