Robins James, Rotnitzky Andrea, Vansteelandt Stijn
Departments of Epidemiology, and Biostatistics, Harvard School of Public Health, 655 Huntington Avenue, Boston, Massachusetts 02115, U.S.A.
Biometrics. 2007 Sep;63(3):650-3. doi: 10.1111/j.1541-0420.2007.00847_2.x.