@article{10_4064_fm_57_3_237_245,
     author = {S. Hildebrand and D. Sanderson},
     title = {Connectivity functions and retracts},
     journal = {Fundamenta Mathematicae},
     pages = {237--245},
     publisher = {mathdoc},
     volume = {57},
     number = {3},
     year = {1965},
     doi = {10.4064/fm-57-3-237-245},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-57-3-237-245/}
}