Database: world_development_indicators
Question: What are the sources for the data of children who finished primary school education in Latin America & Caribbean countries?
SQL: SELECT DISTINCT T2.Source FROM Footnotes AS T1 INNER JOIN Series AS T2 ON T1.Seriescode = T2.SeriesCode INNER JOIN Country AS T3 ON T1.Countrycode = T3.CountryCode WHERE T3.Region = 'Latin America & Caribbean' AND T2.IndicatorName = 'Children out of school, primary'