Nicholas J J, Dixon E W, Hennessy J J, Clark J G, Serry C
Department of Physical Medicine and Rehabilitation, Temple University Hospital, Philadelphia, Pennsylvania, 3401 North Broad Street, Philadelphia, PA 19140, USA.
J Cardiopulm Rehabil. 2000 Nov-Dec;20(6):389-91. doi: 10.1097/00008483-200011000-00009.