APA-ийн эшлэл(7 дахь хэвлэлт)

Ager, D. V. (1963). Principles of paleoecology: An introduction to the study of how and where animals and plants lived in the past. McGraw-Hill.

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

Ager, Derek V. Principles of Paleoecology: An Introduction to the Study of How and Where Animals and Plants Lived in the Past. New York: McGraw-Hill, 1963.

MLA -ийн эшлэл (9 дэх хэвлэлт)

Ager, Derek V. Principles of Paleoecology: An Introduction to the Study of How and Where Animals and Plants Lived in the Past. McGraw-Hill, 1963.