Consider Kesey's other books, such as Sometimes a Great Notion, Demon Box, and Sailor Song.
Consider Tom Wolfe's The Electric Kool-Aid Acid Test, which details the experience of Ken Kesey and his fellow Merry Pranksters on their psychedelic cross-country bus trip.
Consider other works about mental illness, such as Virginia Woolf's Mrs. Dalloway, Sylvia Plath's The Bell Jar, and Susanna Kaysen's Girl, Interrupted.
Consider other works with strong messages about societal oppression, such as Aldous Huxley's Brave New World, George Orwell's 1984, and Kurt Vonnegut's Slaughterhouse Five.