@article{SIGMA_2016_12_a40,
     author = {Konrad Sch\"obel},
     title = {Are {Orthogonal} {Separable} {Coordinates} {Really} {Classified?}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2016},
     volume = {12},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2016_12_a40/}
}