_:b56825537 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/oa#TextQuoteSelector> . _:b56825537 <http://www.w3.org/ns/oa#exact> "frequency" . _:b56825536 <http://www.w3.org/ns/oa#hasSource> <http://ns.inria.fr/covid19/arg/568fec0df53acc098777e861ab6b824bf22ca3e4/0> . _:b56825536 <http://www.w3.org/ns/oa#hasSelector> _:b56825537 .