Roitman, Michael
SIGMA, Symmetry Integrability Geom. Methods Appl. 4, Paper 057, 35 p., electronic only (2008)
Klimyk, Anatoliy U.; Patera, Jiri
SIGMA, Symmetry Integrability Geom. Methods Appl. 4, Paper 002, 57 p., electronic only (2008)