@book{LehnerWilms,
  author    = {Lehner, Martin and Wilms, Falko},
  title     = {Systemisch denken - klipp und klar},
  address   = {Z{\"u}rich},
  publisher      = {Fachhochschule Technikum Wien},
  subject      = {Thought Process},
  language  = {de}
}