1. Occupational Health & Safety Administration 20 CFR. Part 1910, Standard 1910.95: Occupational Noise Exposure.
2. B.D.O. Anderson, R.R. Bitmead, C.R. Johnson, P.v. Kokotović, R.L Kosut, I.M.Y. Mareel, L. Party, and B.D. Riedle. Stability of Adaptive Systems: Passivity and Averaging Analyis. MIT Press, Cambridge, MA, USA, 1986.
3. M.Bodson. Equivalence between adaptive cancellatioin algorithms and linear time-varying compensators. In the 43rd IEEE Conference on Decision and Control, pages 638-643,2004.
4. M. Bodson. Rejection of periodic disturbances of unknown and time-varying frequency. International Journal of Adaptive Control and Signal Processing, 19(2-3):67-88, March-April 2005.
5. L.J Brown and Q. Zhang. Periodic disturbance cancellation with uncertain frequency. Auto-matica, 40(4):631-637, April 2004.