??? ???? ????? (?? ??????? : Leo IV ) (???? ??? - ?????? ?? ????? ???) ??? ?? ??????? ?????? ??????? ?? ??? ?? ?? ?? ?? ???? ??? ? ?? ??? ?? ??? ?????? ??? ???.
Wikipedia contributors, "List of popes," Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=List_of_popes&oldid=268921163 (accessed February 9, 2009).