@article{MA_1981__9_17_292978,
     author = {Antoni Smoluk},
     title = {Invariant approximations},
     journal = {Mathematica Applicanda},
     publisher = {mathdoc},
     volume = {9},
     number = {17},
     year = {1981},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/item/MA_1981__9_17_292978/}
}