'Overall conclusions' (Energy Engineering, 2017), 'Wave and Tidal Generation Devices: Reliability and availability', Chap. 12, pp. 199-200, DOI: 10.1049/PBRN018E_ch12
IET Digital Library, https://digital-library.theiet.org/;jsessionid=1m5w95gab3u5g.x-iet-live-01content/books/10.1049/pbrn018e_ch12