Inspiratory muscle training using an incremental endurance test alleviates dyspnea and improves functional status in patients with chronic heart failure - Laoutaris, Ioannis; Dritsas, Athanasios; Brown, Margaret D; Manginas, Athanasios; Alivizatos, Peter A; Cokkinos, Dennis V (European Journal of Cardiovascular Prevention & Rehabilitation, 2004)