@book{PetschniggSimeonovMairingeretal.,
  author    = {Petschnigg, Ursula and Simeonov, Emil and Mairinger, Daniela and Schmid, Christian},
  title     = {Portfolio f{\"u}r den Mathematikunterricht an Bildungsanstalten f{\"u}r Kindergartenp{\"a}dagogik},
  publisher      = {Fachhochschule Technikum Wien},
  subject      = {Mathematics},
  language  = {de}
}
@book{SimeonovMairingerSchmid,
  author    = {Simeonov, Emil and Mairinger, Daniela and Schmid, Christian},
  title     = {Mathematische Fr{\"u}herziehung - Formen},
  publisher      = {Fachhochschule Technikum Wien},
  subject      = {Mathematics},
  language  = {de}
}