Population Division, United Nations, World Population Prospects: The 2017 Revision, New York, 2017.
 D. Brooker, and L. Duceb, “Well-being and activity in dementia: A comparison of group reminiscence therapy, structured goal-directed group activity, and unstructured time,” Aging & Mental Health, 4, pp. 354-358, 2000.
 B. A. Purves, A. Phinney, W. Hulko, G. Puurveen, A. J. Astell, “Developing CIRCA-BC and exploring the role of the computer as a third participant in conversation,” American Journal of Alzheimer’s Disease & Other Dementias, Vol. 30, No.1, pp. 101-107, 2014.
 N. Kuwahara, S. Abe, K. Yasuda, and K. Kuwabara, “Networked reminiscence therapy for individuals with dementia by using photo and video sharing,” Proc. ASSETS, pp. 125-132, 2006.
 M. Alaoui, and M. Lewkowicz, “A LivingLab Approach to Involve Elderly in the Design of Smart TV Applications Offering Communication Services,” Online Communities and Social Computing, pp. 325-334, 2013.
 A. Kristoffersson, S. Coradeschi, and A. Loutfi, “User-Centered Evaluation of Robotic Telepresence for an Elderly Population,” Proc. 2nd International Workshop on Designing robotic artefacts with user- and experience-centred perspectives at Nordi CHI’10, pp. 1-4, 2010.
 K. Wada, and T. Shibata, “Robot Therapy in a Care House: Results of Case Studies,” Proc. The IEEE International Symposium on Robot and Human Interactive Communication (RO-MAN), pp. 581-586, 2006.
 T. Tamura, S. Yonemitsu, A. Itoh, D. Oikawa, A. Kawakami, Y. Higashi, T. Fujimoto, and K. Nakajima, “Is an entertainment robot useful in the care of elderly people with severe dementia?,” Journal of Gerontoloy: Medical Science, 59A (1), pp. 83-85, 2004.
 M. Heerink, B. Kröse , V. Evers , and B. Wielinga, “The influence of a robot's social abilities on acceptance by elderly users,” RO-MAN, pp. 521 -526, 2006.
 W. D. Stiehl, J. Lieberman, C. Breazeal, L. Basel, R. Cooper, H. Knight, L. Lalla, A. Maymin, and S. Purchase, “The huggable: a therapeutic robotic companion for relational, affective touch,” Proc. The 3rd Consumer Communications and Networking Conference, pp. 1290-1291, 2006.
 D. Lee, T. Yamazaki, and S. Helal, “Robotic companions for smart space interaction,” Pervasive Computing, pp. 78-84, 2009.
 K. Wada and T. Shibata, T. Saito, K. Sakamoto, and K. Tanie, “Psychological and social effects of one year robot assisted activity on elderly people at a health service facility for the aged,” Proc. The IEEE International Conference on Robotics and Automation, pp. 2785-2790, 2005.
 V. B. Morhenn, L. E. Beavin, and P. J. Zak, “Massage increases oxytocin and reduces adrenocorticotropin hormone in humans,” Altern Ther Health Med, 18(6), pp. 11-18, 2012.
 A. Beetz, L. Uvnäs-Moberg, H. Julius, and K. Kotrschal, “Psychosocial and psychophysiological effects of human-animal interactions: the possible role of oxytocin,” Frontiers in Psychology, 3, 234, 2012.
 H. Sumioka, A. Nakae, R. Kanai, and H. Ishiguro, “Huggable communication medium decreases cortisol levels,” Scientific Reports, 3, 3034, 2013.
 R. Yamazaki, L. Christensen, K. Skov, C. Chang, M. F. Damholdt, H. Sumioka, S. Nishio, and H. Ishiguro, “Intimacy in Phone Conversations: Anxiety Reduction for Danish Seniors with Hugvie,” Frontiers in Psychology, Vol. 7, No. 537, pp. 1-9, 2016.
 K. Ogawa, S. Nishio, K. Koda, K. Taura, T. Minato, C. T. Ishii, and H. Ishiguro, “Telenoid: tele-presence android for communication,” SIGGRAPH Emerging Technologies, p. 15, 2011.
 R. Yamazaki, S. Nishio, K. Ogawa, and H. Ishiguro, “Teleoperated Android as an Embodied Communication Medium: A Case Study with Demented Elderlies in a Care Facility,” RO-MAN, pp. 1066-1071, 2012.
 R. Yamazaki, S. Nishio, H. Ishiguro, M. Nørskov, N. Ishiguro, and G. Balistreri, “Acceptability of a Teleoperated Android by Senior Citizens in Danish Society: A Case Study on the Application of an Embodied Communication Medium to Home Care,” International Journal of Social Robotics, Vol. 6, No. 3, pp. 429-442, 2014.
 A. Waytz, J. Heafner, and N. Epley, “The Mind in the Machine: Anthropomorphism Increases Trust in an Autonomous Vehicle,” Journal of Experimental Social Psychology, Vol. 52, pp. 113-117, 2014.
 The National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research, United States, The Belmont Report: Ethical Principles and Guidelines for the Protection of Human Subjects of Research, 1979.
 E. Sedenberg, J. Chuang, and D. Mulligan, “Designing Commercial Therapeutic Robots for Privacy Preserving Systems and Ethical Research Practices Within the Home,” International Journal of Social Robotics, Vol. 8, pp. 575-587, 2016.
 P. P. Verbeek, Moralizing Technology: Understanding and Designing the Morality of Things, University of Chicago Press, 2011.