Assessment of circulatory adjustments during underwater apnoea in elite divers by means of a portable device - Tocco, F; Marongiu, E; Pinna, M; Roberto, S; Pusceddu, M; Angius, L; Migliaccio, G; Milia, R; Concu, A; Crisafulli, A (Acta Physiol (Oxf), 2013)