1. Fans—Design and Operation of Centrifugal, Axial-flow and Cross-flow Fans;Eck,1973
2. Turbomachines—A Guide to Design, Selection and Theory;Balje,1981
3. Axial Flow Fans and Ducts;Wallis,1983
4. Improving cooling tower fan system efficiencies;Monroe;Combustion,1979
5. The influence of impeller gap in free discharging axial-flow fans without guide wheel;Marcinowski;Voith-Forsch. Konstruktion,1958