1999bflm_hadronic.pdf Solutions of the Betchov-Da Rios soliton equation in the anti-De Sitter 3-space, Manuel Barros, Angel Ferrández, Pascual Lucas and Miguel A. Meroño, en
'New Approaches in Nonlinear Analysis', ed. Th. M. Rassias, Hadronic Press Inc., Palm Harbor, Florida, pp. 51-71, 1999.