Tài liệu tham khảo WikiPedia: Ghardaïa http://www.statoids.com/ydz.html http://geonames.nga.mil/ggmagaz/ http://whc.unesco.org/en/list http://whc.unesco.org/en/list/188 http://whc.unesco.org/en/list/?search=&search_by_c...
