Count the different affiliations of the authors of 'The subset sum game revisited'.
How many different affiliations do the authors of 'The subset sum game revisited' have?
SELECT (COUNT(DISTINCT ?answer) AS ?count) WHERE { <https://dblp.org/rec/journals/mst/PieterseW21> <https://dblp.org/rdf/schema#authoredBy> ?x . ?x <https://dblp.org/rdf/schema#primaryAffiliation> ?answer }
<https://dblp.org/rec/journals/mst/PieterseW21>