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.
Brown TM, Holland J, Bokowy KL, Horblyuk R. Can transformational programs aimed at improving hospital management, leadership, and productivity systems affect financial performance? J Hospital Admin. 2013 Jul 30;2(4):111-9.