_:b57752256 <http://www.w3.org/ns/oa#hasSelector> _:b57752257 . _:b57752257 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/oa#TextQuoteSelector> . _:b57752257 <http://www.w3.org/ns/oa#exact> "U" . _:b57752256 <http://www.w3.org/ns/oa#hasSource> <http://ns.inria.fr/covid19/arg/976496c92ea74a516df11ebb445433f724e7f522/0> .