@misc{KappelSchieleBuchholz2017,
  author    = {Kappel, Antonia and Schiele, Holger and Buchholz, Wolfgang},
  title     = {How to capture suppliers' relationships with competitors and complementors? - An approach to supply network mapping using a World Caf{\´e} method, 26th Annual International Purchasing and Supply Education and Research Association (IPSERA) Conference: "Coping with the Future: Picking your Battles", Budapest/Balatonfured, Hungary},
  year      = {2017},
  language  = {en}
}
@misc{KappelSchieleBuchholz2018,
  author    = {Kappel, Antonia and Schiele, Holger and Buchholz, Wolfgang},
  title     = {Supplier relationships with competing customers - How can purchasers find out who is the preferred customer?, 27th Annual International Purchasing and Supply Education and Research Association (IPSERA) Conference: "Purchasing and Supply Chain Management: Fostering Innovation", Athens, Greece.},
  year      = {2018},
  language  = {en}
}