@article{MS2_1980__46_166692,
     author = {Aage Bondesen and Arne Bronsted},
     title = {A dual proof of the upper bound conjecture for convex polytopes.},
     journal = {Mathematica Scandinavica},
     pages = {95--102},
     publisher = {mathdoc},
     volume = {46},
     year = {1980},
     zbl = {0437.52001},
     url = {http://geodesic.mathdoc.fr/item/MS2_1980__46_166692/}
}