@article{brignall:almost,
    AUTHOR = {Brignall, Robert, and Ekhad, Shalosh B., and Smith, Rebecca and Vatter, Vincent},
     TITLE = {Approximations to Permutation Classes}
   JOURNAL = {Discrete Math.},

    VOLUME = {309},

      YEAR = {2009},
     PAGES = {6626--6631},
}