Effect of interval training with non-invasive ventilation in severe chronic obstructive pulmonary disease—a prospective cohort study with matched control group - Fekete, Monika; Kerti, Maria; Fazekas-Pongor, Vince; Balazs, Peter; Csizmadia, Zoltán; Nemeth, Anna N.; Tarantini, Stefano; Varga, Janos T. (Annals of Palliative Medicine, 2021)