RALEVIĆ, P. .; DOBRODOLAC, M. .; ŠVADLENKA, L. .; ŠARAC, D. .; ĐURIĆ, D. . Efficiency and productivity analysis of universal service obligation: a case of 29 designated operators in the European countries. Technological and Economic Development of Economy, v. 26, n. 4, p. 785-807, 12 Jun. 2020.