The MPAA Film Rating History by JamesMoulton1988 on DeviantArt

Movies get a ratings system – Dan The Man Trivia

A History of the X and NC-17 Ratings – The Hollywood Reporter

MPAA Rating Bumper Rated X Remake (1968-1970) by TheAnthonyCorp on DeviantArt

File:X MPAA.png - Wikipedia

The first American film to receive an X rating

Saw X is rated R18 WITH CUTS by the MTRCB in the Philippines : r/saw

6th Season of Ryoko Yonekura's “Doctor-X” starts off to huge ratings

RetroNewsNow on X: 🎬On November 1, 1968, the Motion Picture Association of America's film rating system was officially introduced with the ratings G, M, R & X / X

8 Theatrical Films You May Not Know Were Originally Rated X – Silver Screen Guide

The X-Rated Life – Approved for All Audiences #atozchallenge - The Madlab Post