@article{10_4064_ap_9_1_65_77,
     author = {F. Bierski},
     title = {L'\'ecart restreint de ensembles et son application},
     journal = {Annales Polonici Mathematici},
     pages = {65--77},
     publisher = {mathdoc},
     volume = {9},
     number = {1},
     year = {1960},
     doi = {10.4064/ap-9-1-65-77},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-9-1-65-77/}
}