@article{10_4064_ap_21_1_73_83,
     author = {F. H. Szafraniec},
     title = {Existence theorems for discrete boundary problems},
     journal = {Annales Polonici Mathematici},
     pages = {73--83},
     publisher = {mathdoc},
     volume = {21},
     number = {1},
     year = {1968},
     doi = {10.4064/ap-21-1-73-83},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-21-1-73-83/}
}