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*. 

Wikipedia claims that the 1972 animated movie *[Journey Back to Oz](https://en.wikipedia.org/wiki/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.