Chicago: L. Frank Baum, "Introduction.," The Wizard of Oz Original Sources, accessed April 26, 2024, http://www.originalsources.com/Document.aspx?DocID=6RNLF39FTNUK3GG.
MLA: Baum, L. Frank. "Introduction." The Wizard of Oz, Original Sources. 26 Apr. 2024. http://www.originalsources.com/Document.aspx?DocID=6RNLF39FTNUK3GG.
Harvard: Baum, LF, 'Introduction.' in The Wizard of Oz. Original Sources, retrieved 26 April 2024, from http://www.originalsources.com/Document.aspx?DocID=6RNLF39FTNUK3GG.