Naigles, L. R., Hoff, E., Vear, D., Tomasello, M., Brandt, S., Waxman, S. R., & Childers, J. B. (2009). Flexibility in early verb use: Evidence from a multiple-n dairy study: Vii general discussion. Monographs of the Society for Research in Child Development, 74(2), 91-104. doi:10.1111/j.1540-5834.2009.00520.x.