Earthworks Group

title	ISBN-13	year of publica- tion	other author(s)
50 Simple Things Kids Can Do To Save The Earth	978-0-8335-4472-8	1990
50 Simple Things You Can Do to Save the Earth	978-0-929634-06-7	1989
Fifty Simple Things Kids Can Do to Save the Earth	978-0-8362-2301-9	1990	Earth Works Group (U. S.)
The New 50 Simple Things Kids Can Do to Save the Earth	978-0-7407-7746-2	2009