Henry David Thoreau, Excursions, vol 5, Boston, Houghtonn Mifflin & Company, 1863.
Archives du mot-clé submarine
The nature-experimenter
Glenwood G. Clark, Tiny Toilers and their Works, Londres, J. Coker & Co., 1921, pp. 119-125.
Nemo
Anonyme, « Wonders of Pond Life », Chicago, The Delphian Course, vol. VII, 1913, p. 479.
Sacrifice
Henry Augustin Beers, Initial Studies in American Letters, New York, Chatauqua Press, (1891) 1895, p. 258.