@article{AM2_1982__25_136943,
     author = {Betti Salzberg},
     title = {Buildings and shadows.},
     journal = {Aequationes mathematicae},
     pages = {1--20},
     publisher = {mathdoc},
     volume = {25},
     year = {1982},
     zbl = {0531.20025},
     url = {http://geodesic.mathdoc.fr/item/AM2_1982__25_136943/}
}