@phdthesis{dnb-5836,
  title = {Relativized polynomial hierarchies extending two levels},
  author = {Hans Heller},
  year = {1981},
  url = {http://d-nb.info/821065203},
  researchr = {https://researchr.org/publication/dnb-5836},
  cites = {0},
  citedby = {0},
  school = {Technical University Munich, Germany},
}