Torruellas, W.; Lawrence, B.; Stegeman, G.I.: 'Self-focusing and 2D spatial solitons in PTS', Electronics Letters, 1996, 32, (22), p. 2092-2094, DOI: 10.1049/el:19961400
IET Digital Library, https://digital-library.theiet.org/;jsessionid=7ipt0s2g498n9.x-iet-live-01content/journals/10.1049/el_19961400