Cita APA (7a ed.)

Osborne, M. P., & Murdocca, S. (1998). Polar bears past bedtime. Random House.

Cita Chicago Style (17a ed.)

Osborne, Mary Pope, y Sal Murdocca. Polar Bears Past Bedtime. New York: Random House, 1998.

Cita MLA (8a ed.)

Osborne, Mary Pope, y Sal Murdocca. Polar Bears Past Bedtime. Random House, 1998.