APA-ийн эшлэл(7 дахь хэвлэлт)

Fisher, R. (1991). Heartland of a continent: America's plains and prairies. National Geographic Society.

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

Fisher, Ron. Heartland of a Continent: America's Plains and Prairies. Washington, D.C.: National Geographic Society, 1991.

MLA -ийн эшлэл (9 дэх хэвлэлт)

Fisher, Ron. Heartland of a Continent: America's Plains and Prairies. National Geographic Society, 1991.