1. International Ergnomics Association. http://www.iea.cc/whats/value.html . Accessed 20 April 2016
2. Han, S.H., Kim, K.J., Yun, M.H., et al.: Identifying mobile phone design features critical to user satisfaction. Hum. Factors Man. 14, 15–29 (2004). doi: 10.1002/hfm.10051
3. Dolcourt, J.: Smartphones: when is ‘big’ too big? http://www.cnet.com/news/smartphones-when-is-big-too-big-smartphones-unlocked (2013). Accessed 20 April 2016
4. Fowler, G.A.: Find the best phone-screen size for you. http://www.wsj.com/articles/how-to-find-the-phone-that-fits-your-hand-1395795606 (2014). Accessed 20 April 2016
5. Pelosi, M., Franek, O., Knudsen, B.M., et al.: A grip study for talk and data modes in mobile phones. IEEE Trans. Antennas Propag. 57(4), 856–865 (2009)