@unpublished{ShlapunovTarkhanov2008,
  author  = {Alexander Shlapunov and Nikolai Nikolaevich Tarkhanov},
  title   = {Mixed problems with a parameter},
  institution = {Institut f{\"u}r Mathematik},
  series    = {Preprint},
  number    = {(2004) 02},
  year    = {2008},
}