Convalescent plasma treatment for patients of 80 years and older with COVID-19 pneumonia. - Romon I; Dominguez-Garcia JJ; Arroyo JL; Suberviola B; Cabezón I; Abascal B; Baldeón C; Cuesta A; Portilla R; Casuso E; Ocio E; Briz M (BMC geriatrics, 2021)