'Section 1 - Review and overall requirements' (Control, Robotics and Sensors, 2018), 'Wearable Exoskeleton Systems: Design, control and applications', Chap. sec1, pp. 1-3, DOI: 10.1049/PBCE108E_sec1
IET Digital Library, https://digital-library.theiet.org/;jsessionid=426oqb620oskf.x-iet-live-01content/books/10.1049/pbce108e_sec1