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Curve No.2 (Name: Kolya H. [boy]; Age: 2 months). Curve No.3 (Name: Slavik F. [boy]; Age: 8 months 9 days). Curve No.4 (Name: Leyla M. [girl]; Age: 1 year 19 days). Figure is from [Denisova, M. P. and Figurin, N. L. (1926). Periodic phenomena in the sleep of children. Novoe v refleksologii i fiziologii nervnoi sistemy, 2, 338–345]. This material is provided solely for scientific and educational uses.
