Healthline. https://www.healthline.com/health/childrens-health/stages-of-child-development
Diakses pada 22 Agustus 2020Mott Children’s Hospital. https://www.mottchildren.org/health-library/ue5723
Diakses pada 22 Agustus 2020Verywell Family. https://www.verywellfamily.com/6-year-old-developmental-milestones-620703
Diakses pada 22 Agustus 2020WebMD. https://www.webmd.com/parenting/guide/child-at-6-milestones#1
Diakses pada 22 Agustus 2020