How many {contributed to published work} are to/by {La Vanguardia} ?
How many newspapers are circulated in La Vanguardia?
What is the newspaper circulation of La Vanguardia?
SELECT ( COUNT ( ?w ) AS ?a ) { ?w property:contributed_to_creative_work resource:La_Vanguardia }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P3919> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q511533 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P3919 wd:Q511533 }
8