@article{10.1007/BF02398269,
    Author = {Birkhoff, George D. and Trjitzinsky, W. J.},
    File = {Analytic theory of singular difference equations - BF02398269.pdf},
    Journal = {Acta Mathematica},
    Number = {none},
    Pages = {1 -- 89},
    Publisher = {Institut Mittag-Leffler},
    Title = {{Analytic theory of singular difference equations}},
    URL = {https://doi.org/10.1007/BF02398269},
    Volume = {60},
    Year = {1933},
    bdsk-url-1 = {https://doi.org/10.1007/BF02398269},
    date-added = {2023-08-26 08:19:06 +0200},
    date-modified = {2023-08-26 08:19:06 +0200},
    doi = {10.1007/BF02398269}
}

@article{10.1007/BF02398269, Author = {Birkhoff, George D. and Trjitzinsky, W. J.}, File = {Analytic theory of singular difference equations - BF02398269.pdf}, Journal = {Acta Mathematica}, Number = {none}, Pages = {1 -- 89}, Publisher = {Institut Mittag-Leffler}, Title = {{Analytic theory of singular difference equations}}, URL = {https://doi.org/10.1007/BF02398269}, Volume = {60}, Year = {1933}, bdsk-url-1 = {https://doi.org/10.1007/BF02398269}, date-added = {2023-08-26 08:19:06 +0200}, date-modified = {2023-08-26 08:19:06 +0200}, doi = {10.1007/BF02398269} }