Gaya APA

Arengo, S., Mariani, M. (2011). Classic tales level 2 : the ugly duckling (Ed. 2). United Kingdom: Oxford University Press.

Gaya MLA

Arengo, Sue., Mariani, Mirella. "Classic tales level 2 : the ugly duckling". Ed. 2 United Kingdom: Oxford University Press, 2011. Text.