@InCollection{    Tseitin:1968,
  Author        = "Tseitin, G. S.",
  Editor        = "Slisenko, A. O.",
  BookTitle     = "Studies in mathematics and mathematical logic, Part II",
  date-added    = "2021-08-04 08:07:00 +0200",
  date-modified = "2021-08-04 09:26:41 +0200",
  Pages         = "115--125",
  Title         = "On the complexity of derivations in propositional calculus",
  Year          = "1968",
  File          = "On the complexity of derivations in propositional calculus - Tseitin70.pdf"
}

@InCollection{ Tseitin:1968, Author = "Tseitin, G. S.", Editor = "Slisenko, A. O.", BookTitle = "Studies in mathematics and mathematical logic, Part II", date-added = "2021-08-04 08:07:00 +0200", date-modified = "2021-08-04 09:26:41 +0200", Pages = "115--125", Title = "On the complexity of derivations in propositional calculus", Year = "1968", File = "On the complexity of derivations in propositional calculus - Tseitin70.pdf" }