What types of spatial soliton can be formed based on two-photon-isomerisation? J. C. Liang, Z. B. Cai, Y. Z. Sun, L. Yi and H. C. Wang Eur. Phys. J. D, 55 3 (2009) 685-689 Published online: 04 September 2009 DOI: 10.1140/epjd/e2009-00240-4