Cain, G.D.; Morling, R.C.S.: 'C.C.D. processor for simultaneous time stretching and signal averaging', Electronics Letters, 1977, 13, (9), p. 269-270, DOI: 10.1049/el:19770195
IET Digital Library, https://digital-library.theiet.org/;jsessionid=bj679h23t8nkb.x-iet-live-01content/journals/10.1049/el_19770195