Books, Brochures, and Chapters>Book:  Leopold , Aldo and Schwartz , Charles W. (1989-06-15), A Sand County Almanac, and Sketches Here and There, Oxford University Press, USA, Retrieved on 2012-06-11

Source Material [books.google.com]

Books, Brochures, and Chapters>Book:  Leopold , Aldo (2001-11-15), A Sand County Almanac (Outdoor Essays & Reflections), Oxford University Press, USA, Retrieved on 2011-06-10