“Off on Vacation - But Not Without My Smartphone; [Ab in Den Urlaub - Aber Nicht Ohne Mein Smartphone]”. gis.Business | issn : 1869-9286 16, no. 1 (January 1, 2015): 62–65. Accessed November 8, 2026. https://journal-gis.business/index.php/gisb/article/view/515.