<http://ns.inria.fr/covid19/PMC7302277#body_text> <http://purl.org/dc/terms/subject> "Partial differential equations" . <http://ns.inria.fr/covid19/PMC7302277#body_text> <http://purl.org/dc/terms/subject> "Europe" . <http://ns.inria.fr/covid19/PMC7302277#body_text> <http://purl.org/dc/terms/subject> "Differential equations" .