Health systems resilience during COVID-19. Lessons for building back better (European Observatory on Health Systems and Policy, 2021) Dokumentu-zerrenda https://apps.who.int/iris/rest/bitstreams/1390564/retrieve Xehetasunak 'Health systems resilience during COVID-19. Lessons for building back better' (European Observatory on Health Systems and Policy, 2021) dokumentoaren azalaren zati bat erreprodukzioa