1. E. H. Carr, What is History?, Penguin Books, 1981.
2. J. G. Truxal, Automatic Feedback System Synthesis, McGraw-Hill, New York, NY, 1955.
3. B. C. Kuo, Automatic Control Systems, Prentice-Hall, Englewood Cliffs, NJ, 1987.
4. R. F. Drenick and R. A. Shahbender, “Adaptive servomechanisms,” AIEE Transactions, vol. 76, pp. 286–292, Nov. 1957.
5. J. A. Aseltine, A. R. Mancini, and C. W. Sarture, “A survey of adaptive control systems,” IRE Trans. Aut. Control, vol. 3, pp. 102–108, Dec. 1958.