@unpublished{XiaochunWitt2008,
  author  = {Liu Xiaochun and Ingo Witt},
  title   = {Pseudodifferential calculi on the half-line respecting prescribed asymptotic types},
  institution = {Institut f{\"u}r Mathematik},
  series    = {Preprint},
  number    = {(2002) 06},
  year    = {2008},
}