Lozewicz S, Greenwood L, Walls A F, Gomez E, Davies R J
Department of Respiratory Medicine, St Bartholomew's Centre for Clinical Research, St Bartholomew's Hospital, London, U.K.
Respir Med. 1990 Nov;84(6):499-501. doi: 10.1016/s0954-6111(08)80116-3.