Gray, G.W.; Harrison, K.J.; Nash, J.A.: 'New family of nematic liquid crystals for displays', Electronics Letters, 1973, 9, (6), p. 130-131, DOI: 10.1049/el:19730096
IET Digital Library, https://digital-library.theiet.org/;jsessionid=xvo1l6486quf.x-iet-live-01content/journals/10.1049/el_19730096