- *Â Key to Refs.: 1 Casini et al. 2006, 2 Duffy et al. 2003, 3 File et al. 2001, 4 File et al. 2005, 5 Fournier et al. 2007, 6 Francis et al. 2006, 7 Ho et al. 2007, 8 Howes et al. 2004, 9 Kreijkamp-Kaspers et al. 2004, 10 Kritz-Silverstein et al. 2003, 11 Le Bars et al. 2002, 12 Mix and Crews 2000, 13 Pipingas et al. 2008, 14 Ryan et al. 2008, 15 Woo et al. 2003
