<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://schema.org/ContactPoint>
<https://www.bukalapak.com/p/buku/biografi/3svp6f-jual-buku-perjalanan-panjang-anak-bumi-biografi-r-m-a-a-koesoemo-oetoyo>