Lopez-Vicente M, Forns J, Esnaola M, Suades-Gonzalez E, Alvarez-Pedrerol M, Robinson O, Julvez J, Garcia-Aymerich J, Sunye J. Physical activity and cognitive trajectories in schoolchildren. Pediatr Exerc Sci. 2016 Aug;91(8):770-5.
Mansfield CA. A consistent method for calibrating contingent value survey data. South Econ J. 1998;64(3):665-81.
Clarkson TB, Anthony MS, Klein KP. Phytoestrogens: can hormone replacement be something you eat? Women's health digest. 1996;1(4):253-5.