Trask, C. (2006). It's easy being green: A handbook for earth-friendly living. Gibbs Smith.
Chicago-viite (17. p.)Trask, Crissy. It's Easy Being Green: A Handbook for Earth-friendly Living. Salt Lake City: Gibbs Smith, 2006.
MLA-viite (9. p.)Trask, Crissy. It's Easy Being Green: A Handbook for Earth-friendly Living. Gibbs Smith, 2006.
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