PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX bench:   <http://localhost/vocabulary/bench/>
PREFIX dc:      <http://purl.org/dc/elements/1.1/>
PREFIX dcterms: <http://purl.org/dc/terms/>
PREFIX foaf:    <http://xmlns.com/foaf/0.1/>
PREFIX swrc:    <http://swrc.ontoware.org/ontology#>

SELECT DISTINCT ?name1 ?name2 
WHERE {
  ?article1 rdf:type bench:Article .
  ?article2 rdf:type bench:Article .
  ?article1 dc:creator ?author1 .
  ?author1 foaf:name ?name1 .
  ?article2 dc:creator ?author2 .
  ?author2 foaf:name ?name2 .
  ?article1 swrc:journal ?journal .
  ?article2 swrc:journal ?journal
  FILTER (?name1<?name2)
}