@phdthesis{Mann2006,
  author      = {Matthias Mann},
  title       = {A non-deterministic call-by-need lambda calculus : proving similarity a precongruence by an extension of Howe's method to sharing},
  type        = {doctoralthesis},
  school      = {Universit{\"a}tsbibliothek Johann Christian Senckenberg},
  year        = {2006},
}