APA-ийн эшлэл(7 дахь хэвлэлт)

Gingrich, N., & Maple, T. (2007). A contract with the Earth. Johns Hopkins University Press.

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

Gingrich, Newt, ба Terry Maple. A Contract with the Earth. Baltimore: Johns Hopkins University Press, 2007.

MLA -ийн эшлэл (9 дэх хэвлэлт)

Gingrich, Newt, ба Terry Maple. A Contract with the Earth. Johns Hopkins University Press, 2007.