Παραπομπή σε μορφή APA (7η εκδ.)

Hays, S. P. (2009). The American people & the national forests: The first century of the U.S. Forest Service. University of Pittsburgh Press.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Hays, Samuel P. The American People & the National Forests: The First Century of the U.S. Forest Service. Pittsburgh, Pennsylvania: University of Pittsburgh Press, 2009.

Παραπομπή σε μορφή MLA (9th εκδ.)

Hays, Samuel P. The American People & the National Forests: The First Century of the U.S. Forest Service. University of Pittsburgh Press, 2009.