How many {published in} are to/by {Naturwissenschaften} ?
Naturwissenschafter publishes how items?
How many things published in {Naturwissenschaften} ?
SELECT ( COUNT ( ?u ) AS ?j ) { ?u property:published_in resource:Naturwissenschaften }
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/P1433> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q324878 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1433 wd:Q324878 }
6122