_:b57673092 <http://www.w3.org/ns/oa#hasSource> <http://ns.inria.fr/covid19/arg/e1e16f7e22d04879de8412d4cb0f05d4419d8fc2/50> . _:b57673092 <http://www.w3.org/ns/oa#hasSelector> _:b57673093 . _:b57673093 <http://www.w3.org/ns/oa#exact> "mast cell density" . _:b57673093 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/oa#TextQuoteSelector> .