{ "items" : [
    { "id" : "http://ns.inria.fr/covid19/PMC7099242#title"
      "properties" : {
        "http://purl.org/dc/terms/subject" : [ "Economics of transport and utility industries",
          "Aviation industry",
          "1670s in science",
          "Airlines",
          "Pressure vessels",
          "Aviation safety",
          "Microorganisms",
          "Aerospace engineering"] } } }
