“Real and digital - From the virtual image of the factual; [Real und digital – vom virtuellen Bild des Faktischen]”, gis.Business | issn : 1869-9286, vol. 23, no. 1, pp. 19–23, Jan. 2022, Accessed: Nov. 08, 2026. Available: https://journal-gis.business/index.php/gisb/article/view/444