1. Albertini, F., Sontag, E., & Maillot, V. (1993). Uniqueness of weights for neural networks. In R. Mammone (Ed.), Artificial neural networks with applications in speech and vision. London: Chapman and Hall.
2. Babister, A.W. (1967). Transcendental functions satisfying nonhomogeneos linear differential equations. New York: Macmillan.
3. Bohn, E.V. (1963). The transform analysis of linear systems. Reading, MA: Addison-Wesley.
4. The inverse of the error function;Carlitz;Pacific J. Math.,1963
5. Approximation by superposition of a sigmoidal function;Cybenko;Math. Control, Signals and Systems,1989