Generation of a Fast Healthcare Interoperability Resources (FHIR)-based Ontology for Federated Feasibility Queries in the Context of COVID-19: Feasibility Study - Rosenau, Lorenz; Majeed, Raphael W.; Ingenerf, Josef; Kiel, Alexander; Kroll, Björn; Köhler, Thomas; Hans-Ulrich Prokosch; Gruendner, Julian (JMIR Medical Informatics, 2022)