There are some what around 40 books in the OZ series written by L. Frank Baum’. A kindle version of the most famous 14 stories has been complied with beautiful illustration.

All fourteen of L. Frank Baum’s Oz books, are as follows
The Wonderful Wizard of Oz (1900)* Includes Original Illustrations by W.W. Denslow!
The Marvelous Land of Oz (1904)
Ozma of Oz (1907)
Dorothy and the Wizard in Oz (1908)
The Road to Oz (1909)
The Emerald City of Oz (1910)
The Patchwork Girl of Oz (1913)
Tik-Tok of Oz (1914)
The Scarecrow of Oz (1915)
Rinkitink in Oz (1916)
The Lost Princess of Oz (1917)
The Tin Woodman of Oz (1918)
The Magic of Oz (1919)
Glinda of Oz (1920)

Though most of these books are available for free on net. But if you are feeling lazy about searching around then you can easily download it for your little ones for just $0.99. Almost a dollar. They are all evergreen books of OZ.
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