Payne, D.N.; Gambling, W.A.: 'Preparation of water-free silica-based optical-fibre waveguide', Electronics Letters, 1974, 10, (16), p. 335-336, DOI: 10.1049/el:19740265
IET Digital Library, https://digital-library.theiet.org/;jsessionid=3pwoe63gsk30i.x-iet-live-01content/journals/10.1049/el_19740265