Ludin, D. ., W. . Wellbrock, W. . Gerstlberger, E. . Müller, S. . . Noller, and S. . Ruchti. “Changes in Shopping Behavior Under the Aspect of Sustainability and the COVID-19 Pandemic.”. European Journal of Sustainable Development, vol. 11, no. 2, June 2022, p. 142, doi:10.14207/ejsd.2022.v11n2p142.