1. (1) Bleier, F. P., Fan Handbook, (1998), pp. 4.28-4.38, McGraw-Hill, New York.
2. (2) Wallis, R. A., Axial Flow Fans and Ducts, (1983), pp. 309, John Wiley & Sons Inc.
3. (3) Cho, J. S. and Cho, L. S., Experimental Study on the Aerodynamic Characteristics of a Two-Stage and a Counter-Rotating Axial Flow Fan, Transactions of the Korean Society of Mechanical Engineers, Vol. 23, No. 8(B), (2001), pp. 1048-1062.
4. (4) Strack, W. C., Knip, G., Weisbrich, A. L., Godston, J., and Bradly, E., Technology and Benefits of Aircraft Counter Rotation Propellers, NASA TM 82983, (1982).
5. (5) Kodama, Y., Hayashi, H., Fukano, T. and Tanaka, K., Experimental Study on the Characteristics of Fluid Dynamics and Noise of a Counter-Rotating Fan, Transactions of the Japan Society of Mechanical Engineers, Vol. 60, No. 576(B), (1994), pp. 2764-2779.