<https://www.toxic-web.co.uk/blog/2011/10/12/advanced-jquery-background-image-slideshow/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.toxic-web.co.uk/blog/2011/10/12/advanced-jquery-background-image-slideshow/?replytocom=748>