@article{10_4064_cm_24_1_117_119,
     author = {Jan W\'ojcik},
     title = {On sums of three squares},
     journal = {Colloquium Mathematicum},
     pages = {117--119},
     publisher = {mathdoc},
     volume = {24},
     number = {1},
     year = {1971},
     doi = {10.4064/cm-24-1-117-119},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-24-1-117-119/}
}