Benjamin Franklin (1838). “The Works of Benjamin Franklin; Containing Several Political and Historical Tracts Not Included in Any Former Edition, and Many Letters, Official and Private, Not Hitherto Published; with Notes and a Life of the Author”, p.113
Mark Twain, William Dean Howells (1960). “Mark Twain-Howells Letters: The Correspondence of Samuel L. Clemens and William D. Howells, 1872-1910”, Belknap Press