@article{10_4064_ap_37_2_119_129,
     author = {Z. Krzeszowiak-Dybiec},
     title = {Existence of differentiable solutions of a system of functional equations of first order},
     journal = {Annales Polonici Mathematici},
     pages = {119--129},
     publisher = {mathdoc},
     volume = {37},
     number = {2},
     year = {1980},
     doi = {10.4064/ap-37-2-119-129},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-37-2-119-129/}
}