How many {archives at} are to/by {Harvard University} ?
Which is the number of the archives at Harvard University?
How many archives are at Harvard University?
SELECT ( COUNT ( ?o ) AS ?x ) { ?o property:archives_at resource:Harvard_University }
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/P485> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q13371 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P485 wd:Q13371 }
29