In 1987, how many papers did the authors of 'Simulation of Guerilla Warfare' publish?
Count the papers published by the authors of 'Simulation of Guerilla Warfare' in 1987.
SELECT DISTINCT (COUNT(?answer) AS ?count) WHERE { <https://dblp.org/rec/conf/simulationstechnik/Stahel87> <https://dblp.org/rdf/schema#authoredBy> ?x . ?answer <https://dblp.org/rdf/schema#authoredBy> ?x . ?answer <https://dblp.org/rdf/schema#yearOfPublication> '1987' }
<https://dblp.org/rec/conf/simulationstechnik/Stahel87>