1. Roundabouts: A State of the Art in Germany;Brilon;National Roundabout Conference,2005
2. Test of Roundabouts with Double-Lane or Single-Lane Markings but with Double-Lane Circulatory Roadways. Federal Ministry of Transport, Construction and Housing, Department of Road Construction;Brilon;Road Traffic,2004
3. Turbo Roundabouts Design Principles and Safety Performance;Fortuijn;Journal of the Transportation Research Board,2009
4. Turbo Roundabouts Estimation of Capacity;Fortuijn;Journal of the Transportation Research Board,2009