1. Bertrand, C., Bourdeau, L.: Research interviews by Skype: a new data collection method. In: Esteves, J. (Ed.) Proceedings from the 9th European Conference on Research Methods, pp. 70–79. IE Business School, Spain (2010)
2. Dionisio, J.D.N., Burns III, W.G., Gilbert, R.: 3D virtual worlds and the metaverse: Current status and future possibilities. ACM Comput. Surv. 45(3), 1–38. Article no. 34. https://doi.org/10.1145/2480741.2480751
3. Dlib c++ library.: http://dlib.net/
4. Ekman, P., Friesen, W.V.: The repertoire or nonverbal behavior: categories, origins, usage, and coding. Semiotica 1, 49–98 (1969)
5. Gerkey B., Smart, W., Quigley, M.: Programming Robots with ROS. O’Reilly Media (2015)