_:b56930348 <http://www.w3.org/ns/oa#hasSelector> _:b56930349 . _:b56930349 <http://www.w3.org/ns/oa#exact> "frequency" . _:b56930349 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/oa#TextQuoteSelector> . _:b56930348 <http://www.w3.org/ns/oa#hasSource> <http://ns.inria.fr/covid19/arg/5af4f9f25a2b24b5a7d20dd3120e597b250806e7/3> .