APA-ийн эшлэл(7 дахь хэвлэлт)

Hannan, B. (2009). The riddle of the world: A reconsideration of Schopenhauer's philosophy. Oxford University Press.

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

Hannan, Barbara. The Riddle of the World: A Reconsideration of Schopenhauer's Philosophy. Oxford ; New York: Oxford University Press, 2009.

MLA -ийн эшлэл (9 дэх хэвлэлт)

Hannan, Barbara. The Riddle of the World: A Reconsideration of Schopenhauer's Philosophy. Oxford University Press, 2009.