Save the Children published in March 2017 a report, “Windows into Early Learning and Development”. The report presents research on early childhood development, and uses recent IDELA (International Development and Early Learning Assessment) evidence to investigate factors influencing child development, and ECD approaches that work for children in low- and middle-income countries.
You can find the report in English at https://i.stci.uk/sites/default/files/libraries/IDELA%20REPORT.pdf