acid test
- https://www.dead.net/archives/1965/photos/can-you-pass-acid-test
- https://www.dead.net/archives/1965/artwork/acid-test-poster-1965-signed-ken-kesey
- https://www.dead.net/archives/1965/artwork/grateful-dead-folk-story-acid-test-poster
- https://www.dead.net/archives/1966/artwork/fillmore-acid-test-poster
- https://www.dead.net/archives/1966/artwork/trips-festival-san-francisco-poster