<https://staceyltokunaga.blogspot.com/2020/03/las-vegas-icons-history-of-slot-machines.html>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://staceyltokunaga.blogspot.com/2020/03/las-vegas-icons-history-of-slot-machines.html>