Chicago:
Mark Twain, "Foreword," Mark Twain’s Letters— Volume 1 (1835-1866), ed. Paine, Albert Bigelow, 1861-1937 and trans. Townsend, R.S. in Mark Twain’s Letters—Volume 1 (1835-1866) (New York: A. L. Burt Company, 1916), Original Sources, accessed July 5, 2025, http://www.originalsources.com/Document.aspx?DocID=32S7T4N8MSDQE4R.
MLA:
Twain, Mark. "Foreword." Mark Twain’s Letters— Volume 1 (1835-1866), edited by Paine, Albert Bigelow, 1861-1937, and translated by Townsend, R.S., in Mark Twain’s Letters—Volume 1 (1835-1866), Vol. 22, New York, A. L. Burt Company, 1916, Original Sources. 5 Jul. 2025. http://www.originalsources.com/Document.aspx?DocID=32S7T4N8MSDQE4R.
Harvard:
Twain, M, 'Foreword' in Mark Twain’s Letters— Volume 1 (1835-1866), ed. and trans. . cited in 1916, Mark Twain’s Letters—Volume 1 (1835-1866), A. L. Burt Company, New York. Original Sources, retrieved 5 July 2025, from http://www.originalsources.com/Document.aspx?DocID=32S7T4N8MSDQE4R.