@article{10_4171_dm_248,
     author = {Alex Postnikov and Victor Reiner and Lauren Williams},
     title = {Faces of generalized permutohedra},
     journal = {Documenta mathematica},
     pages = {207--273},
     year = {2008},
     volume = {13},
     doi = {10.4171/dm/248},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/dm/248/}
}