• DOI http://dx.doi.org/10.18177/sym.2014.54.sr.10844
  • PDF https://www.jstor.org/stable/26574363

  • DOI http://dx.doi.org/10.18177/sym.2014.54.sr.10629
  • PDF https://www.jstor.org/stable/26574366

  • DOI http://dx.doi.org/10.18177/sym.2012.52.sr.924
  • PDF https://www.jstor.org/stable/26564877