@article{CMH_1932__4_138574,
     author = {L. Kollros},
     title = {Suites r\'ecurrentes de cercles et de sph\`eres.},
     journal = {Commentarii mathematici Helvetici},
     pages = {97--101},
     publisher = {mathdoc},
     volume = {4},
     year = {1932},
     zbl = {58.1225.05},
     url = {http://geodesic.mathdoc.fr/item/CMH_1932__4_138574/}
}