Cita APA (7a ed.)

National Geographic Society., Cook, D. W., & Peele, W. T. (1977). Europe: Celtic Europe. National Geographic Society.

Cita Chicago Style (17a ed.)

National Geographic Society., David W. Cook, y William T. Peele. Europe: Celtic Europe. Washington, D.C.: National Geographic Society, 1977.

Cita MLA (9a ed.)

National Geographic Society., et al. Europe: Celtic Europe. National Geographic Society, 1977.