@misc{Hummel1999,
  author    = {Hummel, Detlev},
  title     = {M{\"a}rkte, Pl{\"a}tze, Finanzsysteme: L{\"a}nderbericht USA},
  year      = {1999},
  language  = {de}
}
@misc{HummelSteden1999,
  author    = {Hummel, Detlev and Steden, Philip},
  title     = {M{\"a}rkte, Pl{\"a}tze, Finanzsysteme: L{\"a}nderbericht Großbritannien},
  year      = {1999},
  language  = {de}
}