Aldo Leopold (2013). “Aldo Leopold: A Sand County Almanac & Other Writings on Conservation and Ecology: (Library of America #238)”, p.548, Library of America
Aldo Leopold (2013). “Aldo Leopold: A Sand County Almanac & Other Writings on Conservation and Ecology: (Library of America #238)”, p.473, Library of America
Aldo Leopold (2013). “Aldo Leopold: A Sand County Almanac & Other Writings on Conservation and Ecology: (Library of America #238)”, p.557, Library of America
Aldo Leopold (2013). “Aldo Leopold: A Sand County Almanac & Other Writings on Conservation and Ecology: (Library of America #238)”, p.556, Library of America
Aldo Leopold (2013). “Aldo Leopold: A Sand County Almanac & Other Writings on Conservation and Ecology: (Library of America #238)”, p.18, Library of America