 Siegelmann, H. T. 

 Siegelmann, H. T. (B. DasGupta, H. T. Siegelmann and E. Sontag)  On a learnability question associated to neural networks with continuous activations  1994 
 Siegelmann, H. T. (B. DasGupta, H. T. Siegelmann and E. Sontag)  On the complexity of training neural networks with continuous activation functions  1995 
