@article{SIGMA_2020_16_a134,
     author = {Bjorn K. Berntson and Ernest G. Kalnins and Willard Miller Jr.},
     title = {Toward {Classification} of 2nd {Order} {Superintegrable} {Systems} in {3-Dimensional} {Conformally} {Flat} {Spaces} with {Functionally} {Linearly} {Dependent} {Symmetry} {Operators}},
     journal = {Symmetry, integrability and geometry: methods and applications},
     year = {2020},
     volume = {16},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SIGMA_2020_16_a134/}
}