Walls, L. D. (1995). Seeing new worlds: Henry David Thoreau and nineteenth-century natural science. University of Wisconsin Press.

Walls, Laura Dassow. Seeing New Worlds: Henry David Thoreau and Nineteenth-century Natural Science. Madison, WI: University of Wisconsin Press, 1995.

Walls, Laura Dassow. Seeing New Worlds: Henry David Thoreau and Nineteenth-century Natural Science. University of Wisconsin Press, 1995.