List down the country names of countries that have a GNP lower than 1000 and have Dutch as their language.
GNP lower than 1000 refers to GNP < 1000; Dutch as their language refers to `Language` = 'Dutch';
SELECT T2.Name FROM CountryLanguage AS T1 INNER JOIN Country AS T2 ON T1.CountryCode = T2.Code WHERE T2.GNP < 1000 AND T1.IsOfficial = 'T' AND T1.Language = 'Dutch'