Question: Who featured both as Darth Vader in the first movie and also authored " Voices and silences"?
Answer(s):
answer: James Earl Jones

SPARQL query:
#MANUAL SPARQL
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
{
  SELECT DISTINCT ?f1
  WHERE {
    ns:m.0f2y0 ns:film.film_character.portrayed_in_films ?y .  # Darth Vader
    ?y ns:film.performance.film ?f1 .
    ?f1 ns:film.film.initial_release_date ?d .
  }
  ORDER BY ?d
  LIMIT 1
}
  ns:m.0f2y0 ns:film.film_character.portrayed_in_films ?y .  # Darth Vader
  ?y ns:film.performance.actor ?x ; 
     ns:film.performance.film ?f .
  FILTER (?f1 = ?f)?x ns:book.author.works_written ns:m.067z76z . 
}