_:b56598336 <http://www.w3.org/ns/oa#hasSource> <http://ns.inria.fr/covid19/arg/8e14619d4a09ad90f6efed43d8804493fa387b80/3> . _:b56598337 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/oa#TextQuoteSelector> . _:b56598337 <http://www.w3.org/ns/oa#exact> "frequency" . _:b56598336 <http://www.w3.org/ns/oa#hasSelector> _:b56598337 .