Walls, L. D. (1995). Seeing new worlds: Henry David Thoreau and nineteenth-century natural science. University of Wisconsin Press.
Lua i Stíl Chicago (17ú heag.)Walls, Laura Dassow. Seeing New Worlds: Henry David Thoreau and Nineteenth-century Natural Science. Madison WI: University of Wisconsin Press, 1995.
Lua MLA (9ú heag.)Walls, Laura Dassow. Seeing New Worlds: Henry David Thoreau and Nineteenth-century Natural Science. University of Wisconsin Press, 1995.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.