High Quality Content by WIKIPEDIA articles! This page is a supplement to List of Oz books featuring published books, often by small publishing houses, that are not generally considered canonical Oz books, making them apocryphal. As the Baum Oz books are in the public domain, no clearance needs to be obtained to write and publish (professionally or otherwise) fiction about the Oz characters, making the question of canonicity somewhat subjective. Additionally, both of Jack Snow`s Oz books are in the public domain in the United States, as are Ruth Plumly Thompson`s The Royal Book of Oz, Kabumpo in Oz, The Wishing Horse of Oz, Captain Salt in Oz, Handy Mandy in Oz, The Silver Princess in Oz, and Ozoplaning with the Wizard of Oz, making the distinctive elements in those books usable as public domain content. The most dramatic changes in her books are in The Lost King of Oz and The Giant Horse of Oz, both of which remain protected under U.S. copyright law, and has rendered some known manuscripts unpublishable. The Oz books of John R. Neill, Rachel R. Cosgrove, and Eloise Jarvis McGraw and her daughter Lauren are all protected under U.S. copyright, making their characters and developments unusable by others without permission.