: 'in brief', Electronics Letters, 2018, 54, (8), p. 464-464, DOI: 10.1049/el.2018.0982
IET Digital Library, https://digital-library.theiet.org/;jsessionid=1j34shfq75bpq.x-iet-live-01content/journals/10.1049/el.2018.0982