@article{10_4153_CMB_1977_049_0,
     author = {Nowakowski, Richard and Rival, Ivan},
     title = {The {Spectrum} of a {Finite} {Lattice:} {Breadth} and {Length} {Techniques}},
     journal = {Canadian mathematical bulletin},
     pages = {319--329},
     year = {1977},
     volume = {20},
     number = {3},
     doi = {10.4153/CMB-1977-049-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1977-049-0/}
}