<https://unacademy.com/course/potuttmilll-9-aam-vkuppu-mutl-12-aam-vkuppu-vraiyilaannn-putiy-tmilll-puttkm/B4WHYEUI>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://unacademy.com/course/9-12/B4WHYEUI>