Adaptations of The Wizard of Oz
"The Wonderful Wizard of Oz" is a 1900 children's novel written by American author L. Frank Baum. Since its first publication in 1900, it has been adapted many times: for film, television, theatre, books, comics, games, and other media.Many of the television programs cited in this list are not strict adaptions of "The Wizard of Oz"; rather, they have reinterpreted aspects of the book, such as characters and plot, to create sequels, prequels or side-plots, which are inspired by Baum's original text.
There are over 40 canonical Oz books, including 14 by Baum, all of which are considered "official" sequels or prequels to "The Wonderful Wizard of Oz". In addition, the following books use the Oz milieu as settings for their tales:Kevin Scott Collier. "The Wonderful Animated World of the Wizard of Oz: The Good, The Bad and The Ugly!" CreateSpace Independent Publishing Platform, 2018.
Copyright status of The Wizard of Oz and related works in the United States
Alexander Volkov's six Oz books were published in the Soviet Union, so they are subject to Russian copyright law. The first book – "The Wizard of the Emerald City" – was published in 1939, when "The Wizard of Oz" was still copyrighted. "The Wizard of the Emerald City" is an adaptation of "The Wizard of Oz", borrowing liberally from the original book without even crediting Baum.
The subsequent four books were published between 1963 and 1970, and the last one – "The Secret of the Deserted Castle" – was published in 1980. At the time of publication, "The Wizard of Oz" and "The Land of Oz" were in the public domain, but the other Oz books were still copyrighted. However, Volkov's books are mostly original sequels to "The Wizard of the Emerald City", so whether they are infringing or not is difficult to say. Barely any of the elements from later Oz books are featured in Volkov's works, so most likely they were not infringing.