_:b57453380	<http://www.w3.org/ns/oa#hasSource>	<http://ns.inria.fr/covid19/arg/6e9f45e8ed2f2faec24918941f8efc8ac5fb4ce8/0> .
_:b57453380	<http://www.w3.org/ns/oa#hasSelector>	_:b57453381 .
_:b57453381	<http://www.w3.org/ns/oa#exact>	"density" .
_:b57453381	<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>	<http://www.w3.org/ns/oa#TextQuoteSelector> .