@TechReport{      porous,
  Author        = {Lefaucheux, Engel and Ouaknine, Jo{\"e}l and Purser, David and Worrell, James},
  date-added    = "2021-02-22 09:27:08 +0100",
  date-modified = "2021-02-22 09:27:17 +0100",
  Title         = "Porous invariants",
  File          = "Porous invariants - porous\_invariants21 - a - h.pdf"
}

@TechReport{ porous, Author = {Lefaucheux, Engel and Ouaknine, Jo{\"e}l and Purser, David and Worrell, James}, date-added = "2021-02-22 09:27:08 +0100", date-modified = "2021-02-22 09:27:17 +0100", Title = "Porous invariants", File = "Porous invariants - porous_invariants21 - a - h.pdf" }