@article{WalaLeutgeb,
  author    = {Wala, Thomas and Leutgeb, Daniel},
  title     = {Investitionscontrolling. Systematische Identifikation und Umsetzung von Wertsteigerungspotenzialen},
  series = {Controlling. 21-MalBindestrich-Controlling f{\"u}r die Praxis},
  journal   = {Controlling. 21-MalBindestrich-Controlling f{\"u}r die Praxis},
  editor    = {Eschenbach, Rolf and Baum{\"u}ller, Josef and Siller, Helmut},
  pages     = {247ff},
  subject      = {Investment},
  language  = {de}
}
@article{Wala,
  author    = {Wala, Thomas},
  title     = {Die betriebswirtschaftliche Klausur: Controlling},
  series = {WISU},
  journal   = {WISU},
  number    = {5},
  pages     = {588ff},
  subject      = {Controlling},
  language  = {de}
}