Chester M, Woodhead M A, Millard F J C, Jonathan D A
Department of Thoracic Medicine, St James's Hospital, London SW12 8HW
Department of Otolaryngology, St George's Hospital, London SW17 0QT
Br Med J (Clin Res Ed). 1987 Dec 12;295(6612):1561-2. doi: 10.1136/bmj.295.6612.1561-c.