1. 1. J. D. Kueck, M. Olszewski, D. A. Casada, J. S. Hsu, P. J. Otaduy, and L. M. Tolbert, ―Assessment of methods for estimating motor efficiency and load under field conditions,‖ Lockheed Martin Energy Research Corp., Oak Ridge, TN, Rep. ORNL/TM-13165, Jan. 1996.
   2.  J. S. Hsu and P. L. Sorenson, ―Field assessment of induction motor efficiency through air-gap torque,‖ IEEE Trans. Energy Conversion, vol. 11, pp. 489–494, Sept. 1996.
   3.  High Efficiency Motor Selection Handbook, Bonneville Power Administration (BPA), Portland, OR, 1990, p. 21.
   4.  W. D. Biesemeyer and J. Jowett, ―Facts and fiction of HVAC motor measuring for energy savings,‖ Arizona Department of Commerce, Energy Office, Phoenix, AZ, Biesemeyer #116, 1994
   5. P. L. Alger, The Nature of Induction Machines. New York: Gordon and Breach, 1965.
   6. J. S. Hsu, H. H. Woodson, and W. F. Weldon, ―Possible errors in measurement of air-gap torque pulsations of induction motors,‖ IEEE Trans. Energy Conversion, vol. 7, pp. 202–208, Mar. 1992.
   7. J. S. Hsu, ―Monitoring of defects in induction motors through air-gap torque observation,‖ IEEE Trans. Ind. Applicat., vol. 31, pp. 1016–1021, Sept./Oct. 1995.
   8. C. L. Becnel et al., ―Determining motor efficiency by field testing,‖ IEEE Trans. Ind. Applicat., vol. IA23, pp. 440–443, May/June 1987.
   9. A. H. Bonnett, ―An update on ac induction motor efficiency,‖ IEEE Trans. Ind. Applicat., vol. 30, pp. 1362–1372, Sept./Oct. 1994
   10. IEEE Standard Test Procedure for Polyphase Induction Motors and Generators, IEEE Standard 112- 1991, 1991.
   11. H. E. Jordan and A. Gattozzi, ―Efficiency Testing of Induction Machines,‖ in Conf. Rec. IEEE-IAS Annu. Meeting, Cleveland, OH, Sept. 30–Oct. 5, 1979, pp. 284–289.
   12. R. E. Oesterlei, ―Motor efficiency test methods— Apple and oranges?,‖ Power Transmission Design, vol. 22, no. 5, pp. 41–43, May 1980.
   13. P. G. Cummings, W. D. Bowers, and W. J. Martiny, ―Induction motor efficiency test methods,‖ IEEE Trans. Ind. Applicat., vol. IA-17, pp. 253–272, May/June 1981
   14. NEMA Standards Publication No. MG1, National Electrical Manufacturers Association (NEMA), Washington, D.C., 1993.
   15. Motor Master, Version 2.1., 98504-3165.K, Washington State Energy Office, Olympia, WA.
   16. R. L. Nailen, ―Can field tests prove motor efficiency?,‖ in Conf. Rec. IEEE I&CPS Tech. Conf., Baltimore, MD, May 2–5, 1988, pp. 110–116.
   17. J. S. Hsu, P. J. Otaduy, and J. D. Kueck, ―Efficiency and reliability assessments of retrofitted high-efficiency motors,‖ in Conf. Rec. IEEEIAS Annu. Meeting, Lake Buena Vista, FL, Oct. 8–12, 1995, pp. 2745–2751.
   18. J. S. Hsu and B. P. Scoggins, ―Field test of motor efficiency and load changes through air-gap torque,‖ IEEE Trans. Energy Conversion, vol. 10, pp. 471–477, Sept. 1995.
   19. Understanding AC motor efficiency,‖ Electrical Apparatus Service Association, St. Louis, MO