@article{10_4064_ap_38_1_47_49,
     author = {Thomas Hasanis},
     title = {A new characterization of the sphere in $R^3$},
     journal = {Annales Polonici Mathematici},
     pages = {47--49},
     publisher = {mathdoc},
     volume = {38},
     number = {1},
     year = {1980},
     doi = {10.4064/ap-38-1-47-49},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-38-1-47-49/}
}