1. Yoshio Kodama, et al.: Experimental study on the characteristics of fluid dynamics and noice of a counter-rotating fan (1st report, Effects of the supporter shape of the electric motor and the distance between two rotors on the characteristics ), The Japan society of mechanical engineers, Vol.60, No. 576, pp. 144–151, (1994–8).
2. Yoshio Kodama, et al.: Experimental study on the characteristics of fluid dynamics and noise of a counter-rotating fan (2st report, Effects of the combination of the number of two rotor blades, the solidity and the tip clearance), The Japan society of mechanical engineers, Vol.60, No. 576, pp. 152–159, (1994–8).
3. Toru Shigemitsu, Junichiro Fukutomi, et al.: The Performance and the Similarity Law of Small-Sized Axial Fan and the Possibility of Adoption of Contra-Rotating Rotors, Proceedings of the 9th International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows (ISAIF9), 8∼11 September 2009, Gyeongju, Korea.
4. Wang Yangang, Liu Bo, et al.: Flow Field Investigation of Dual Stage Counter-Rotating Compressor. Journal of Northwestern Polytechnical University, Vol.24, pp.97–101, (2006).
5. Yuki Okabe, et al.: On the internal flow of contra-rotating small-sized axial fan, The Japan society of mechanical engineers, 2009. 11.7–8.