APA-ийн эшлэл(7 дахь хэвлэлт)

Tweed, W. C. (2010). Uncertain path: A search for the future of national parks. University of California Press.

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

Tweed, William C. Uncertain Path: A Search for the Future of National Parks. Berkeley: University of California Press, 2010.

MLA -ийн эшлэл (9 дэх хэвлэлт)

Tweed, William C. Uncertain Path: A Search for the Future of National Parks. University of California Press, 2010.