Rita, Rita, et al. “The Correlation Between Brain Derived Neurotrophic Factor (BDNF) Level and Motor Development of Children Aged Under 2 Years in Timor Tengah Selatan Nusa Tenggara Timur”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 23, no. 2, July 2015, pp. 164-72, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/4330.