1. Barnett K (1972) A theoretical construct of the concepts of touch as they relate to nursing. Nurse Res 21:102–110. doi: 10.1097/00006199-197203000-00002
2. Brooke J (1996) SUS: a quick and dirty usability scale. In: Jordan PW, Thomas B, Weerdmeester BA, McClelland AL (eds) Usability evaluation in industry. Taylor & Francis, London
3. Brooks AG, Arkin RC (2007) Behavioral overlays for non-verbal communication expression on a humanoid robot. Auton Robots 22(1):55–74. doi: 10.1007/s10514-006-9005-8
4. Chang C, Hsu C, Lin C (2003) A practical guide to support vector classification. In: Taipei, Taiwan, vol 106
5. Chang C, Lin C (2001) LIBSVM: a library for support vector machines. http://www.csie.ntu.edu.tw/cjlin/libsvm . Accessed 25 July 2013