3) Overstall PW, Exton-Smith AN, Imms FJ, Johnson AL: Falls in the elderly related to postural imbalance. British Medical Journal 29: 261-264, 1977
4) Exton-Smith AN: Clinical Manifestation, in Care of Elderly. Meeting the Challenge of Dependency. ed. by Exiton-Smith AN, Grelimley Evans J, London, Academic Press, 1977.