A Barnstormer in Oz a 1982 novel by Philip José Farmer and is based on the setting and characters of L. Frank Baum's The Wonderful Wizard of Oz.
An adult fantasy that takes only Baum’s first book as having occurred. In it, an older Dorothy living in Kansas has a son , Hank Stover that stumbles into Oz and falls in love with Glinda. This book has garnered both excellent and terrible reviews and may be worth a look. Includes sex and violence and is not recommended for children.