<http://ns.inria.fr/covid19/PMC4195612#body_text> <http://purl.org/dc/terms/subject> "Medical mnemonics" . <http://ns.inria.fr/covid19/PMC4195612#body_text> <http://purl.org/dc/terms/subject> "Physical chemistry" . <http://ns.inria.fr/covid19/PMC4195612#body_text> <http://purl.org/dc/terms/subject> "Independent cities in the United States" .