Uttam, D.: 'Measurement of intermodal delay in a dual-mode optical fibre', Electronics Letters, 1985, 21, (22), p. 1031-1033, DOI: 10.1049/el:19850732
IET Digital Library, https://digital-library.theiet.org/;jsessionid=6jhk61p6jtopi.x-iet-live-01content/journals/10.1049/el_19850732