'The slip energy recovery system for wound rotor induction motors' (Energy Engineering, 1988), 'Variable Frequency AC Motor Drive Systems', Chap. 10, pp. 349-379, DOI: 10.1049/PBPO008E_ch10 IET Digital Library, https://digital-library.theiet.org/;jsessionid=1ulvvy4ob8l6h.x-iet-live-01content/books/10.1049/pbpo008e_ch10