A Novel Symbolic Type Neural Network Model- Application to River Flow   Forecasting
  In this paper we introduce a new symbolic type neural tree network called symbolic function network (SFN) that is based on using elementary functions to model systems in a symbolic form. The proposed formulation permits feature selection, functional selection, and flexible structure. We applied this model on the River Flow forecasting problem. The results found to be superior in both fitness and sparsity. 
George S. Eskander, and Amir F. Atiya