1. The use of pipe bends as flow meters;Addison;Engineering,1938
2. Flow conditions in a vertical bend;Keutner;Z. Ver. Deut. Ing. (Ger.),1933
3. New method of water measurement by use of elbows in a pipe line;Jacobs;J. Electr. Power & Gas,1911
4. Flow of Water through 6-inch Pipe bends." Technical Bulletin No. 577;Yarnell,1937
5. On the Measurement of Pressure and Velocity of Water Stream in a Curved Pipe;Kawada,1929