Ohashi, M.; Shiraki, K.: 'Er3+-doped multicomponent glass core fibre amplifier pumped at 1.48 μm', Electronics Letters, 1991, 27, (23), p. 2143-2145, DOI: 10.1049/el:19911327 IET Digital Library, https://digital-library.theiet.org/;jsessionid=50bhu4bhei568.x-iet-live-01content/journals/10.1049/el_19911327