Interstate-guide.com: Interstate 71(页面存档备份,存于互联网档案馆) Historic photos: 1963 aerial view of I-71 construction between 17th and 5th avenues in Columbus, Ohio Gasoline
维基共享资源上的相关多媒体资源:23号美国国道 US Highways from US 1 to US 830 US-23 endpoint photos Michigan US 23 ends US-23 on Michigan Highways(页面存档备份,存于互联网档案馆) (Christopher
(原始内容存档于2014-01-01). Map of Maryland showing the Highways (地图). Maryland Geological Survey. 1910 [2008-06-30]. (原始内容存档于2008-08-17). Map of Maryland showing State