Langer Robert D, White Emily, Lewis Cora E, Kotchen Jane M, Hendrix Susan L, Trevisan Maurizio
Department of Family and Preventive Medicine, University of California, San Diego, La Jolla, CA 92037, USA.
Ann Epidemiol. 2003 Oct;13(9 Suppl):S107-21. doi: 10.1016/s1047-2797(03)00047-4.