Escolano-Pérez, Elena, and Angel Blanco-Villaseñor. “The Longitudinal Measurement of Change: Intraindividual Variability in Behavior and Interindividual Differences Observed in Childhood”. Anales De Psicología Annals of Psychology, vol. 31, no. 2, Apr. 2015, pp. 545-51, doi:10.6018/analesps.31.2.166361.