@article{10_14708_cm_v8i2_5520,
     author = {T. Sty\'s},
     title = {Twierdzenie {Hopfa} dla pewnego eliptycznego uk{\l}adu r\'owna\'n liniowych drugiego rz\k{e}du},
     journal = {Commentationes Mathematicae},
     pages = { 143--146},
     publisher = {mathdoc},
     volume = {8},
     number = {2},
     year = {1964},
     doi = {10.14708/cm.v8i2.5520},
     language = {pl},
     url = {http://geodesic.mathdoc.fr/articles/10.14708/cm.v8i2.5520/}
}