Harstad Ingunn, Jacobsen Geir W
Department of Public Health and General Practice, Norwegian University of Science and Technology, Clinic of Thoracic and Occupational Medicine, St. Olavs Hospital, Norway.
Tidsskr Nor Laegeforen. 2012 Jan 10;132(1):14-6. doi: 10.4045/tidsskr.11.0566.