APA (7th ed.) Citation

Keats, E. J. (1991). Un dia de nieve. Puffin Books.

Chicago Style (17th ed.) Citation

Keats, Ezra Jack. Un Dia De Nieve. New York: Puffin Books, 1991.

MLA (8th ed.) Citation

Keats, Ezra Jack. Un Dia De Nieve. Puffin Books, 1991.