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Diakses pada 1 Maret 2020LEARNINGPOTENTIAL.https://www.learningpotential.gov.au/is-your-child-ready-for-big-school
Diakses pada 1 Maret 2020FEE.https://fee.org/articles/harvard-study-shows-the-dangers-of-early-school-enrollment/
Diakses pada 1 Maret 2020HARVARD.https://news.harvard.edu/gazette/story/2018/11/when-starting-school-younger-children-are-more-likely-to-be-diagnosed-with-adhd-study-says/
Diakses pada 1 Maret 2020