Various. Encyclopaedia Britannica, 11th Edition, "Map" to "Mars" Volume 17, Slice 6.
Cita Chicago (17th ed.)Various. Encyclopaedia Britannica, 11th Edition, "Map" to "Mars" Volume 17, Slice 6.
Cita MLA (9th ed.)Various. Encyclopaedia Britannica, 11th Edition, "Map" to "Mars" Volume 17, Slice 6.
Atenció: Aquestes cites poden no estar 100% correctes.