Arcà, Andrea (2004). "The topographic engravings of the Alpine rock-art: fields, settlements, and agricultural landscapes". In Chippindale, C.; Nash, G. (eds.). The figured landscapes of Rock-Art. Cambridge University Press. pp. 318–349. Archived from the original on March 26, 2023. Retrieved December 2, 2014.
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archive.aramcoworld.com
Parry, James (January 2004). "Mapping Arabia". Saudi Aramco World. 55: 20–37. Archived from the original on 2018-07-27. Retrieved 2018-07-27.
Ormeling, F.J. (1986-12-31). "Eduard Imhof (1895–1986)". International Cartographic Association. Archived from the original on 2018-09-04. Retrieved 2018-07-27.
Arcà, Andrea (2004). "The topographic engravings of the Alpine rock-art: fields, settlements, and agricultural landscapes". In Chippindale, C.; Nash, G. (eds.). The figured landscapes of Rock-Art. Cambridge University Press. pp. 318–349. Archived from the original on March 26, 2023. Retrieved December 2, 2014.
Ormeling, F.J. (1986-12-31). "Eduard Imhof (1895–1986)". International Cartographic Association. Archived from the original on 2018-09-04. Retrieved 2018-07-27.