'Frequency-adaptive periodic control' (Energy Engineering, 2016), 'Periodic Control of Power Electronic Converters', Chap. 5, pp. 153-180, DOI: 10.1049/PBPO082E_ch5
IET Digital Library, https://digital-library.theiet.org/;jsessionid=4ji5fi2ftc1r7.x-iet-live-01content/books/10.1049/pbpo082e_ch5