APA-ийн эшлэл(7 дахь хэвлэлт)

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

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

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

MLA -ийн эшлэл (9 дэх хэвлэлт)

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