Instrumental-Variables Simultaneous Equations Model of Physical Activity and Body Mass Index: The Coronary Artery Risk Development in Young Adults (CARDIA) Study.
Meyer KA, Guilkey DK, Tien HC, Kiefe CI, Popkin BM, Gordon-Larsen P. Instrumental-Variables Simultaneous Equations Model of Physical Activity and Body Mass Index: The Coronary Artery Risk Development in Young Adults (CARDIA) Study. Am J Epidemiol. 2016 09 15; 184(6):465-76.