@article{05241571, title = {From }, journal = {SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]}, volume = {3}, year = {2007}, zbl = {1131.70004}, language = {en}, url = {http://dml.mathdoc.fr/item/05241571} }
Petrera, Matteo; Ragnisco, Orlando. From . SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only], Tome 3 (2007) . http://gdmltest.u-ga.fr/item/05241571/