"Periodichno izdanie." . . "Периодично издание" . . . "Bulgarien." . . "Bŭlgarska akademii︠a︡ na naukite." . . "Wirtschaftsgeographie." . . "Geografii︠a︡ periodichno izdanie." . . "География периодично издание" . . . "Problems of geography" . "Problems of geography"@bg . . "Problemi na geografii︠a︡ta" . . . . . . . . . . . "Проблеми на географията = Problems of geography" . . "Проблеми на географията" . "Periodicals" . "Problemi na geografii︠a︡ta = Problems of geography"@bg . . . "Problemi na geografijata" . . .