Davis, Kadian; Owusu, Evans B.; Marcenaro, Lucio; Jun Hu, ; Regazzoni, Carlo S.; Feijs, Loe: 'Pervasive sensing for social connectedness' (Healthcare Technologies, 2017), 'Enhanced Living Environments: From models to technologies', Chap. 3, pp. 49-79, DOI: 10.1049/PBHE010E_ch3
IET Digital Library, https://digital-library.theiet.org/;jsessionid=3qedd5a1f4l21.x-iet-live-01content/books/10.1049/pbhe010e_ch3