• DOI http://doi.org/10.18177/sym.2017.57.itm.11346
  • PDF https://www.jstor.org/stable/26574460

  • DOI http://dx.doi.org/10.18177/sym.2015.55.itm.10865
  • PDF https://www.jstor.org/stable/26574398

  • DOI http://dx.doi.org/10.18177/sym.2013.53.rev.10531
  • PDF https://www.jstor.org/stable/26564925

  • DOI http://dx.doi.org/10.18177/sym.2013.53.sr.10387
  • PDF https://www.jstor.org/stable/26564918