How many papers did the authors of 'Rate-revenue-cost of service simulation of a natural gas utility' publish in 1973?
Count the papers published by the authors of 'Rate-revenue-cost of service simulation of a natural gas utility' in 1973.
SELECT DISTINCT (COUNT(?answer) AS ?count) WHERE { <https://dblp.org/rec/conf/wsc/Blumenthal73> <https://dblp.org/rdf/schema#authoredBy> ?x . ?answer <https://dblp.org/rdf/schema#authoredBy> ?x . ?answer <https://dblp.org/rdf/schema#yearOfPublication> '1973' }
<https://dblp.org/rec/conf/wsc/Blumenthal73>