Hirshberg David A, Zubizarreta José R
aDepartment of Statistics, Columbia University, New York, NY; bDepartment of Health Care Policy, Harvard Medical School, Boston, MA; and cDepartment of Statistics, Faculty of Arts and Sciences, Harvard University, Cambridge, MA.
Epidemiology. 2017 Nov;28(6):812-816. doi: 10.1097/EDE.0000000000000735.