@article {ClGu2018,
    author = {Claesson, Anders and Gu\eth mundsson, Bjarki \'{A}g\'{u}st},
     title = {Enumerating permutations sortable by {$k$} passes through a
              pop-stack},
   journal = {Adv. in Appl. Math.},
  fjournal = {Advances in Applied Mathematics},
    volume = {108},
      year = {2019},
     pages = {79--96},
      issn = {0196-8858},
       doi = {10.1016/j.aam.2019.04.002},
       url = {https://doi.org/10.1016/j.aam.2019.04.002},
}