On $F$-Quadratic Stochastic Operators
  In this paper we introduce a notion of $F-$ quadratic stochastic operator. For a wide class of such operators we show that each operator of the class has unique fixed point. Also we prove that any trajectory of the $F$-quadratic stochastic operator converges to the fixed point exponentially fast. 
U.A.Rozikov and U.U.Jamilov