LACKO, Roman - HAJDUOVÁ, Zuzana - ZAWADA, Marcin. The Efficiency of Circular Economies: A Comparison of Visegrád Group Countries. - Registrovaný: Scopus. In Energies : [Journal of Related Scientific Research, Technology Development, Engineering, and the Studies in Policy and Management]. - Basel : MDPI. ISSN 1996-1073, 2021, vol. 14, no. 6, pp. [1-13] online. VEGA 1/0240/20.