<http://ns.inria.fr/covid19/PMC7159541#body_text>	<http://purl.org/dc/terms/subject>	"Hiking equipment" .
<http://ns.inria.fr/covid19/PMC7159541#body_text>	<http://purl.org/dc/terms/subject>	"Nitrogen(\u22123) compounds" .
<http://ns.inria.fr/covid19/PMC7159541#body_text>	<http://purl.org/dc/terms/subject>	"Environmental data" .