@article{10_37236_325,
     author = {Mark Dukes and Robert Parviainen},
     title = {Ascent sequences and upper triangular matrices containing non-negative integers},
     journal = {The electronic journal of combinatorics},
     year = {2010},
     volume = {17},
     doi = {10.37236/325},
     zbl = {1230.05008},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/325/}
}