26.04.2004
Effect of firmness of mattress on chronic non-specific low-back pain: randomised, double-blind, controlled, multicentre trial
F.M. Kovacs, V. Abraira, A. Peńa, J.G. Martin-Rodríguez, M. Sánchez-Vera, E. Ferrer, D. Ruano, P. Guillén, M. Gestoso, A. Muriel, J. Zamora, M.T. Gil del Real, N. Mufraggi
The Lancet, 2003; 362: 1599-1604