<http://ns.inria.fr/covid19/PMC7217127#body_text>	<http://purl.org/dc/terms/subject>	"Hydraulic engineering" .
<http://ns.inria.fr/covid19/PMC7217127#body_text>	<http://purl.org/dc/terms/subject>	"Companies based in Ann Arbor, Michigan" .
<http://ns.inria.fr/covid19/PMC7217127#body_text>	<http://purl.org/dc/terms/subject>	"1st century" .