_:b56688652 <http://www.w3.org/ns/oa#hasSelector> _:b56688653 . _:b56688653 <http://www.w3.org/ns/oa#exact> "frequency" . _:b56688653 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/oa#TextQuoteSelector> . _:b56688652 <http://www.w3.org/ns/oa#hasSource> <http://ns.inria.fr/covid19/arg/7d14338dbc13d014f4066aa98c7e74673f3d58e5/0> .