Hartwig, G. (1869). The Polar World: A popular description of Man and nature in the Arctic and Antarctic regions of the globe. By Dr. G. Hartwig. With eight chromoxylographic plates, three maps, and numerous woodcuts (1a. ed.). Longmans, Green, and Co.
Chicago-referens (17:e uppl.)Hartwig, G. The Polar World: A Popular Description of Man and Nature in the Arctic and Antarctic Regions of the Globe. By Dr. G. Hartwig. With Eight Chromoxylographic Plates, Three Maps, and Numerous Woodcuts. 1a. ed. Londres: Longmans, Green, and Co, 1869.
MLA-referens (9:e uppl.)Hartwig, G. The Polar World: A Popular Description of Man and Nature in the Arctic and Antarctic Regions of the Globe. By Dr. G. Hartwig. With Eight Chromoxylographic Plates, Three Maps, and Numerous Woodcuts. 1a. ed. Longmans, Green, and Co, 1869.