@article{MS2_1978__43_166616,
     author = {Borge Jessen and Anders Thorup},
     title = {The algebra of polytopes in affine spaces.},
     journal = {Mathematica Scandinavica},
     pages = {211--240},
     year = {1978},
     volume = {43},
     zbl = {0398.51009},
     url = {http://geodesic.mathdoc.fr/item/MS2_1978__43_166616/}
}