Chicago: Mark Twain, "Preface," The Innocents Abroad Original Sources, accessed July 5, 2022, http://originalsources.com/Document.aspx?DocID=TXHJK34ZFD1BZWW.
MLA: Twain, Mark. "Preface." The Innocents Abroad, Original Sources. 5 Jul. 2022. http://originalsources.com/Document.aspx?DocID=TXHJK34ZFD1BZWW.
Harvard: Twain, M, 'Preface' in The Innocents Abroad. Original Sources, retrieved 5 July 2022, from http://originalsources.com/Document.aspx?DocID=TXHJK34ZFD1BZWW.