Encyclopaedia Britannica Films, Encyclopaedia Britannica Films, American Geological Institute, & American Geological Institute. (1958). Why do we still have mountains. Chicago, III.: Encyclopaedia Britannica Films.
Citación estilo ChicagoEncyclopaedia Britannica Films, Encyclopaedia Britannica Films, American Geological Institute, y American Geological Institute. Why Do We Still Have Mountains. Chicago, III.: Encyclopaedia Britannica Films, 1958.
Cita MLAEncyclopaedia Britannica Films, Encyclopaedia Britannica Films, American Geological Institute, y American Geological Institute. Why Do We Still Have Mountains. Chicago, III.: Encyclopaedia Britannica Films, 1958.
Precaución: Estas citas no son 100% exactas.