SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/country> <http://dbpedia.org/resource/United_States> . ?x <http://dbpedia.org/property/discipline> ?uri . }
Which fields' academic journals are found in the US?
SELECT DISTINCT ?t WHERE { ?x property:discipline ?t . . ?x property:country resource:United_States }
answer
The fields of the academic journals whose country is the United States are [answer].
The topics of scientific journals whose country is the United States [answer].