Long Judith A, Chang Virginia W, Ibrahim Said A, Asch David A
Veterans Affairs Center for Health Equity Research and Promotion, Leonard Davis Institute of Health Economics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
Ann Intern Med. 2004 Nov 16;141(10):805-12. doi: 10.7326/0003-4819-141-10-200411160-00013.