@PhdThesis{       Heijltjes,
  Author        = "Heijltjes, Willem Bernard",
  date-added    = "2012-04-23 17:08:25 +0200",
  date-modified = "2012-04-23 17:09:01 +0200",
  Title         = "Graphical representation of canonical proof: two case studies",
  Year          = "2011",
  File          = "Graphical representation of canonical proof two case studies - Heijltjes (0) (0) - a - a - q.pdf"
}

@PhdThesis{ Heijltjes, Author = "Heijltjes, Willem Bernard", date-added = "2012-04-23 17:08:25 +0200", date-modified = "2012-04-23 17:09:01 +0200", Title = "Graphical representation of canonical proof: two case studies", Year = "2011", File = "Graphical representation of canonical proof two case studies - Heijltjes (0) (0) - a - a - q.pdf" }