question: Who was a German British art director of M3 and M4
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:film.film_art_director.films_art_directed M3 .
  ?x0 ns:film.film_art_director.films_art_directed M4 .
  ?x0 ns:people.person.nationality ns:m.0345h .
  ?x0 ns:people.person.nationality ns:m.07ssc
  }