Chicago: Lucy Fitch Perkins, "Preface," The Belgian Twins, ed. Hawthorne, Julian, 1846-1934 in The Belgian Twins (New York: Sir Isaac Pitman and Sons, 1894), Original Sources, accessed January 31, 2023, http://www.originalsources.com/Document.aspx?DocID=59S1EH7Y5878AM9.
MLA: Perkins, Lucy Fitch. "Preface." The Belgian Twins, edited by Hawthorne, Julian, 1846-1934, in The Belgian Twins, Vol. 22, New York, Sir Isaac Pitman and Sons, 1894, Original Sources. 31 Jan. 2023. http://www.originalsources.com/Document.aspx?DocID=59S1EH7Y5878AM9.
Harvard: Perkins, LF, 'Preface' in The Belgian Twins, ed. . cited in 1894, The Belgian Twins, Sir Isaac Pitman and Sons, New York. Original Sources, retrieved 31 January 2023, from http://www.originalsources.com/Document.aspx?DocID=59S1EH7Y5878AM9.