# in a curl-command: 
# curl "http://live.dbpedia.org/sparql" --data-urlencode 'query=SELECT ?X ?L ?A ?P WHERE { ?X a <http://dbpedia.org/ontology/Country>; <http://purl.org/dc/terms/subject> <http://dbpedia.org/resource/Category:Member_states_of_the_European_Union>; rdfs:label ?L ; <http://dbpedia.org/property/populationCensus> ?P; <http://dbpedia.org/property/areaKm> ?A . FILTER(lang(?L) = "en" && isNumeric(?A) && isNumeric(?P) )}' -H 'Accept: text/csv'


# or try it via the http://live.dbpedia.org/ SPARQL interface:

 SELECT ?X ?L ?A ?P
    WHERE {  ?X a <http://dbpedia.org/ontology/Country> ;
                <http://purl.org/dc/terms/subject>
          <http://dbpedia.org/resource/Category:Member_states_of_the_European_Union>;
                rdfs:label ?L  ;
                <http://dbpedia.org/property/populationCensus> ?P;
                <http://dbpedia.org/property/areaKm> ?A .
             FILTER(lang(?L) = "en" && isNumeric(?A) && isNumeric(?P) )
          }