<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://cosmouk.cdnds.net/cm/14/31/640x517/53d52c564ecae_-_single-v-relationship-chart-de.png>
<http://www.cosmopolitan.co.uk/love-sex/relationships/a25278/chart-tells-people-why-they-are-single/>