@article{Quaisser1996,
  author    = {Quaisser, Erhard},
  title     = {Schr{\"a}gbilder},
  year      = {1996},
  language  = {de}
}
@article{Quaisser1996,
  author    = {Quaisser, Erhard},
  title     = {Ein Zwillingspaar diophantischer Gleichungen zweiten Grades},
  year      = {1996},
  language  = {de}
}