[1] Hoyniak CP, Bates JE, Staples AD, Rudasill KM, Molfese DL, Molfese VJ.  Child sleep and socioeconomic context in the development of cognitive abilities in early childhood.  Child Development 2019; 90: 1718-1737.

www.evolutionaryparenting.com/normal-toddler-sleep-by-the-numbers

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