1. Transportation Research Board, Special report 209: Highway Capacity Manual, Washington, DC (2000)
2. Transportation Research Board, Special report 209: Highway Capacity Manual, Washington, DC (2010)
3. NCHRP Web-only Document 94.: Appendixes to NCHRP 572.: Roundabout in United States, Transportation Research Board (2006)
4. IRC 65:1976: Recommended Practice for Traffic Rotaries. Indian Road Congress
5. Raff, M.S.; Hart, J.W.: A Volume Warrant for Urban Stop Signs. The Eno Foundation for Highway Traffic Control. Saugatuck (1950)