(en) Marita Moll et Leslie Regan Shade, Seeking Convergence in Policy and Practice : Communications in the Public Interest. Volume 2, Canadian Center for Policy Alternatives, (ISBN0-88627-386-2, lire en ligne), p. 27.
Jesse Ames Spencer, 'THE QUEEN'S MESSAGE' and 'THE PRESIDENT'S REPLY' (full wording), vol. vol. 3, Johnson, Fry, coll. « History of the United States », , Digitised eBook (lire en ligne), p. 542, chap. 10.
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(en) David Mercer, The Telephone : The Life Story of a Technology, Greenwood Publishing Group, , 151 p. (ISBN978-0-313-33207-4, lire en ligne), p. 17.