Cita APA (7a ed.)

Andersen, H. C., & Swan, D. (1994). The Ugly duckling (6th impr. of the 1st ed. of 1986.). Longman.

Cita Chicago Style (17a ed.)

Andersen, H. C., y D.K Swan. The Ugly Duckling. 6th impr. of the 1st ed. of 1986. Harlow: Longman, 1994.

Cita MLA (9a ed.)

Andersen, H. C., y D.K Swan. The Ugly Duckling. 6th impr. of the 1st ed. of 1986. Longman, 1994.