1. Powell, M. J. D.,An Efficient Method for Finding the Minimum of a Function of Several Variables without Calculating Derivatives, Computer Journal, Vol. 7, pp. 155?162, 1964.
2. Zangwill, W. I.,Minimizing a Function without Calculating Derivatives, Computer Journal, Vol. 10, pp. 293?296, 1967.
3. Brent, R. P.,Algorithms for Minimization without Derivatives, Prentice-Hall, Englewood Cliffs, New Jersey, 1973.
4. Himmelblau, D. M.,Applied Nonlinear Programming, McGraw Hill Book Company, New York, New York, 1972.
5. Ortega, J. M., andRheinboldt, W. C.,Iterative Solution of Nonlinear Equations in Several Variables, Academic Press, New York, New York, 1970.