<http://ns.inria.fr/covid19/PMC6818521#body_text>	<http://purl.org/dc/terms/subject>	"Quadrennial sporting events" .
<http://ns.inria.fr/covid19/PMC6818521#body_text>	<http://purl.org/dc/terms/subject>	"Physical chemistry" .
<http://ns.inria.fr/covid19/PMC6818521#body_text>	<http://purl.org/dc/terms/subject>	"British black-and-white films" .