The series that Trouble Under Oz is a sequel to was published by a company. The company is headquartered in New York City.
 The book is illustrated by William Stout and published by Harper Collins. 
 The company is headquartered in New York City and is a subsidiary of News Corp. 
 It is a sequel to Smith's 2005 novel "The Emerald Wand of Oz" which is a further continuation of the Oz series originally started by L. Frank Baum in 1900. 
