Shaoping Bai, ; Virk, Gurvinder S.; Sugar, Thomas G. (ed.): 'Wearable Exoskeleton Systems: Design, control and applications' (Control, Robotics and Sensors, 2018) DOI: 
IET Digital Library, https://digital-library.theiet.org/;jsessionid=49okcpned8vg.x-iet-live-01content/books/ce/pbce108e