1. Spanner EF. British Patent GB521548; May 24, 1940
2. Spanner EF. British Patent GB569000; April 30, 1945
3. Gordon HM, HA. Conduit or pipe. US Patent 630,605; August 8, 1899
4. Kitoh O. Experimental study of turbulent swirling flow in a straight pipe. Journal of Fluid Mechanics. 1991;225:445-479
5. ANSYS. Omega Reynolds Stress model. ANSYS CFX-Solver Theory Guide, Release 17. Canonsburg, PA: ANSYS Inc. pp. 95-96