Fontecha, Jesús; González, Iván; Hervás, Ramón; Bravo, José: 'Human gait analysis for frailty detection-quantitative techniques and procedures' (Healthcare Technologies, 2016), 'Active and Assisted Living: Technologies and Applications', Chap. 10, pp. 179-202, DOI: 10.1049/PBHE006E_ch10
IET Digital Library, https://digital-library.theiet.org/;jsessionid=2p7cabd09c1ql.x-iet-live-01content/books/10.1049/pbhe006e_ch10