DescriptionA4BGmap.svg English: Map of Bulgarian Motorway A4, numbers corrected as of 2012 Date 6 September 2012 Source http://www.wegenwiki.nl/Bestand:A4_BG_map
Bulgaria of Kuber - detailisation Date 20 September 2013 Source https://bg.wikipedia.org/wiki/%D0%A4%D0%B0%D0%B9%D0%BB:BBW_Asparuh.svg Author Спас Колев