Efficiency in Business and Economics Proceedings from the 7th International Conference on Efficiency as a Source of the Wealth of Nations (ESWN), Wrocław 2017 - Dudycz, Tadeusz; Dudycz, Tadeusz; Osbert-Pociecha, Grażyna; Osbert-Pociecha, Grażyna; Brycz, Bogumiła; Brycz, Bogumiła (Springer International Publishing : Imprint: Springer, 2018)