1. The Cultural Nature of Human Development;Rogoff,2003
2. USA Census Bureau, Computer and Internet Use in the United States: 2013, 2014. http://www.census.gov/content/dam/Census/library/publications/2014/acs/acs-28.pdf.
3. Statista–the statistic portal, Percentage of households with home computers in the United Kingdom (UK) from 1985 to 2014, 2015.http://www.statista.com/statistics/289191/household-penetration-of-home-computers-in-the-uk.
4. Statistics Netherlands, ICT usage by households, 2013. http://statline.cbs.nl/StatWeb/publication/?VW=T&DM=SLNL&PA=71102ned&D1=0-3,30-34&D2=0-10&D3=0,l&HD=130422-1118&HDR=G2,T&STB=G1.
5. The Cradle of Culture and What Children Know About Writing and Numbers Before Being Taught;Tolchinsky,2003