1. KPMG, “Trends in Retail 2020,” EHI Retail Institute, 18 04 2012. [Online]. Available: https://www.kpmg.com/DE/de/Documents/trends-retail-2020-executive-summary-2013-kpmg.pdf . [Accessed 04 09 2016].
2. Handelszeitung, “Handelszeitung,” [accessed on 02/09/16]. [Online]. Available: http://www.handelszeitung.at/handelszeitung/shopping-malls-erhoehen-marktanteil-129908 . [Accessed 03 09 2016].
3. G. Inc, “Hype-Cycle-Mobile-Device-Technologies,” 2016. [Online]. Available: https://www.gartner.com/doc/3374017/hype-cycle-mobile-device-technologies . [Accessed 04 09 2016].
4. Vittorio M. N. Passaro (. e. al., “Sensors | Free Full-Text | Sensors for Indoor Mapping and Navigation,” MDPI, 5 2016. [Online]. Available: http://www.mdpi.com/1424-8220/16/5/655 . [Accessed 04 09 2016].
5. a. S. Z. Kourosh Koshelham, “Sensors for Indoor Mapping an Navigation, an references therin,” Sensors, vol. 16, no. 655, 2016.