Spatial solitons supported by localized gain in nonlinear optical waveguidesC.-K. Lam, C.-K. Lam, B. A. Malomed, B. A. Malomed, K. W. Chow, K. W. Chow, P. K.A. Wai and P. K.A. WaiEur. Phys. J. Special Topics, 173 (2009) 233-243DOI: https://doi.org/10.1140/epjst/e2009-01076-8