Zhelyazkova, Donka Dimitrova, Petrova, Nevena Possibilities for Improvement of the Service, Provided by Energo-Pro Varna JSC to End Domestic Customers in the City of Varna,
Институт за икономически изследвания при БАН, 2020, pp. 166 - 192, ISSN 0205-3292 (print).