<http://ns.inria.fr/covid19/PMC3808761#title>	<http://purl.org/dc/terms/subject>	"Cities in ancient Greece" .
<http://ns.inria.fr/covid19/PMC3808761#title>	<http://purl.org/dc/terms/subject>	"Safety engineering" .
<http://ns.inria.fr/covid19/PMC3808761#title>	<http://purl.org/dc/terms/subject>	"Temples of Apollo" .