Ludin, Daniela, Wanja Wellbrock, Erika Müller, Wolfgang Gerstlberger, Kristina Kljevkovic, and Daniel Michel. 2021. “The Necessity of Domestic Flights at Business Trips — A Theoretical and Empirical Study Under the Aspect of Climate-Friendly Alternatives”. Journal of Strategic Innovation and Sustainability 16 (3). https://articlearchives.co/index.php/JSIS/article/view/5133.