@article{DCG_1993__10_2_131261,
     author = {Beifang Chen},
     title = {On the {Euler} {Characteristic} of {Finite} {Unions} of {Convex} {Sets.}},
     journal = {Discrete & computational geometry},
     pages = {79--94},
     publisher = {mathdoc},
     volume = {10},
     number = {2},
     year = {1993},
     zbl = {0783.52001},
     url = {http://geodesic.mathdoc.fr/item/DCG_1993__10_2_131261/}
}