@incollection{Ruf2021,
  author    = {Oliver Ruf},
  title     = {What is Design Theory?},
  series = {Purgar (Ed.): The Palgrave Handbook of Image Studies},
  publisher = {Palgrave Macmillan},
  address   = {Cham},
  isbn      = {978-3-030-71829-9},
  doi       = {10.1007/978-3-030-71830-5\_47},
  pages     = {779 -- 798},
  year      = {2021},
  language  = {en}
}