1. Gartner_Q2 (2017) Gartner says demand for 4G smartphones in emerging markets spurred growth in second quarter of 2017. https://www.gartner.com/newsroom/id/3788963. Accessed 14 July 2018
2. Gartner_Q4 (2017) Gartner says worldwide sales of smartphones recorded first ever decline during the fourth quarter of 2017. https://www.gartner.com/newsroom/id/3859963. Accessed 11 July 2018
3. Statista_a (2018) Number of available applications in the Google Play Store from December 2009 to June 2018. https://www.statista.com/statistics/266210/number-of-available-applications-in-the-google-play-store/. Accessed 13 July 2018
4. Statista_b (2018) Growth of available mobile apps at Google Play worldwide from 2nd quarter 2015 to 1st quarter 2018. https://www.statista.com/statistics/185729/google-play-quarterly-growth-of-available-apps/. Accessed 13 July 2018
5. Statista_c (2018) Cumulative number of apps downloaded from the Google Play as of May 2016 (in billions). https://www.statista.com/statistics/281106/number-of-android-app-downloads-from-google-play/. Accessed 14 July 2018