@book{WalaHaslehner,
  author    = {Wala, Thomas and Haslehner, Franz},
  title     = {Kostenrechnung, Budgetierung und Kostenmanagement},
  edition   = {2. Auflage},
  publisher = {Linde},
  publisher      = {Fachhochschule Technikum Wien},
  subject      = {Cost Accounting},
  language  = {de}
}
@book{Wala,
  author    = {Wala, Thomas},
  title     = {Klausurtraining Kostenrechnung},
  publisher      = {Fachhochschule Technikum Wien},
  subject      = {Cost Accounting},
  language  = {de}
}