Lennon RP, Demetriou TJ, Khalid MF, Van Scoy LJ, Miller EL, Dong H, Zgierska AE. Characteristics and outcomes among hospitalized COVID-19-positive patients in a nonurban environment. Mil Med. 2021 Nov 2;186(11-12):1088-92. doi: 10.1093/milmed/usab044
Gracia Baena JM, Calaf Vall I, Zielonka M, Marsal Mora JR, Godoy P, Worner Diz F. Risk factors and comorbidities associated with severe aortic stenosis: a case-control study. Rev Clin Esp. 2021 May 23;221(5):249-57. doi: 10.1016/j.rce.2020.01.010.