Cita APA

National Geographic Society (U.S.). Special Publications Division. (1971). As we live and breathe: The challenge of our environment. [National Geographic Society.

Citación estilo Chicago

National Geographic Society (U.S.). Special Publications Division. As We Live and Breathe: The Challenge of Our Environment. Washington: [National Geographic Society, 1971.

Cita MLA

National Geographic Society (U.S.). Special Publications Division. As We Live and Breathe: The Challenge of Our Environment. [National Geographic Society, 1971.