Ludin, D., Wellbrock, W., Müller, E., Gerstlberger, W., Kljevkovic, K. and Michel, D. 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 (Aug. 2021). DOI:https://doi.org/10.33423/jsis.v16i3.4439.