Niederhauser, Mike (March 2002). "Modern Roundabouts in Maryland"(PDF). Maryland State Highway Administration. Archived from the original(PDF) on October 1, 2011. Retrieved November 15, 2010.
Uhl, G. Clinton; Bruce, Howard; Shaw, John K. (October 1, 1930). Report of the State Roads Commission of Maryland (1927–1930 ed.). Baltimore: Maryland State Roads Commission. p. 232. Retrieved November 16, 2010.
Bonnell, Robert O.; Bennett, Edgar T.; McMullen, John J. (November 2, 1956). Report of the State Roads Commission of Maryland (1955–1956 ed.). Baltimore: Maryland State Roads Commission. pp. 193–194. Retrieved November 16, 2010.
books.google.com
Clark, William Bullock (1899). Report on the Highways of Maryland. Baltimore: Maryland Geological Survey. p. 251. Retrieved November 16, 2010.
Maryland State Roads Commission (1960). Maryland: Official Highway Map(PDF) (Map). Baltimore: Maryland State Roads Commission.
roads.maryland.gov
Highway Information Services Division (December 31, 2013). Highway Location Reference. Maryland State Highway Administration. Retrieved November 15, 2010.
Niederhauser, Mike (March 2002). "Modern Roundabouts in Maryland"(PDF). Maryland State Highway Administration. Archived from the original(PDF) on October 1, 2011. Retrieved November 15, 2010.