1. Aerodynamic Characteristics of Wind Assisted Vehicle Shapes;Retzlaff,1989
2. Private communication, Dept. of Highways, Province of Saskatchewan.
3. H.A. Panofsky and J.A. Dutton, Atmospheric Turbulence, John Wiley, New York, p. 121.
4. Turbulent flow over a low hill;Jackson;Q.J.R. Meteol. Soc.,1975