@phdthesis{Ifland2014,
  author      = {Marianus Ifland},
  title       = {Feedback-Generierung f{\"u}r offene, strukturierte Aufgaben in E-Learning-Systemen},
  type        = {doctoralthesis},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year        = {2014},
}