What official sequels have there been to the famous 1939 MGM movie The Wizard of Oz? There have been tons of movies and TV shows based on L. Frank Baum's book The Wonderful Wizard of Oz, most recently the NBC show Emerald City (which is really bad by the way).
Wikipedia claims that the 1972 animated movie Journey Back to Oz is an official sequel, but is that right? Are there any others? Note that I'm specifically interested in movies or TV shows authorized by MGM.