@article{10_37236_259,
     author = {Tsoy-Wo Ma},
     title = {Higher chain formula proved by combinatorics},
     journal = {The electronic journal of combinatorics},
     year = {2009},
     volume = {16},
     number = {1},
     doi = {10.37236/259},
     zbl = {1226.05010},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/259/}
}