(Earth Works Group (U.S. (1989). 50 simple things you can do to save the earth. Earthworks Press.
Chicago-viite (17. p.)(Earth Works Group (U.S. 50 Simple Things You Can Do to Save the Earth. .Berkeley, CA: Earthworks Press, 1989.
MLA-viite (9. p.)(Earth Works Group (U.S. 50 Simple Things You Can Do to Save the Earth. Earthworks Press, 1989.
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