Earth Works Group (Estados Unidos) & Earth Works Group. (1990). 50 simple things kids can do to save the earth. Andrews and McMeel.

Earth Works Group (Estados Unidos) and Earth Works Group. 50 Simple Things Kids Can Do to Save the Earth. Kansas City: Andrews and McMeel, 1990.

Earth Works Group (Estados Unidos) and Earth Works Group. 50 Simple Things Kids Can Do to Save the Earth. Andrews and McMeel, 1990.