A family of exactly solvable radial quantum systems on space of non-constant curvature with accidental degeneracy in the spectrum. Ragnisco, Orlando; Riglioni, Danilo — 2010 SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]
Superintegrable oscillator and Kepler systems on spaces of nonconstant curvature via the Stäckel transform. Ballesteros, Ángel; Enciso, Alberto; Herranz, Francisco J.; Ragnisco, Orlando; Riglioni, Danilo — 2011 SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]