Walls, L. D. (1995). Seeing new worlds: Henry David Thoreau and nineteenth-century natural science. University of Wisconsin Press.
Chicago-referens (17:e uppl.)Walls, Laura Dassow. Seeing New Worlds: Henry David Thoreau and Nineteenth-century Natural Science. Madison WI: University of Wisconsin Press, 1995.
MLA-referens (9:e uppl.)Walls, Laura Dassow. Seeing New Worlds: Henry David Thoreau and Nineteenth-century Natural Science. University of Wisconsin Press, 1995.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.