Kałasznik, D., A. Kokoszka, G. Kubacki, E. Mijalska, and J. Platje. “A CASE STUDY ON LOGISTIC PROBLEMS IN THE COLLECTION OF REFUND BOTTLES”. Economic and Environmental Studies, vol. 3, Nov. 2020, pp. 267-75, https://czasopisma.uni.opole.pl/index.php/ees/article/view/2842.