Question: Which director, Piers Haggard or Penelope Spheeris, is best known as a documentary film director whose works include the trilogy titled "The Decline of Western Civilization"?
Sentence (from "Penelope Spheeris"): Penelope Spheeris (born December 2, 1945 or 1946; sources differ) is an American film director, producer and screenwriter.
Relevant evidence: Yes