Angold, Russ: 'Ekso Bionics' (Control, Robotics and Sensors, 2018), 'Wearable Exoskeleton Systems: Design, control and applications', Chap. 14, pp. 363-378, DOI: 10.1049/PBCE108E_ch14 IET Digital Library, https://digital-library.theiet.org/;jsessionid=3gmsmkllob6er.x-iet-live-01content/books/10.1049/pbce108e_ch14