X-Rated Movies: 28 Provocative Films That Challenged the MPAA – IndieWire

X (MPAA), Rating System Wiki

The History of The First X-Rated Movie - Rare

Adult rating, Rating System Wiki

CLOCKWORK ORANGE, Stanley Kubrick, X Rated Ratings Box Original Movie Theater Poster - Original Vintage Movie Posters

CLOCKWORK ORANGE' TO GET AN 'R' RATING - The New York Times

File:MPAA X RATING (block).svg - Wikipedia

IPX Rating System: What It Means And Why You Should Know

The first American film to receive an X rating

The X-Rated Cut Of 'RoboCop' Is Available To Stream On Prime Right Now

X Community Notes used to challenge ads by Apple and others - 9to5Mac