References
  1. ↑ Jump up to:1.0 1.1 Wijnhoven, T. M., et al. (2004). “Assessment of gross motor development in the WHO Multicentre Growth Reference Study.” Food Nutr Bull 25(1 Suppl): S37-45.
  2.  Ramsey D, Scoto M, Mayhew A, Main M, Mazzone ES, Montes J, et al. (2017) Revised Hammersmith Scale for spinal muscular atrophy: A SMA specific clinical outcome assessment tool. PLoS ONE 12(2): e0172346. doi:10.1371/journal. pone.0172346
  3.  Illingworth RS. The normal child: Some problems of the early years and their treatment, 1991