Topological electro-vacuum solutions in extended gravity
  Spherically symmetric static topological black hole solutions associated with some extended higher order gravitational models in the presence of a Maxwell-field are derived by means of simple Lagrangian method, based on spherically symmetric reduction. Some new topological black hole solutions are presented and the validity of the First Law is investigated, and in these cases an expression for the energy is provided. 
Guido Cognola, Emilio Elizalde, Lorenzo Sebastiani and Sergio Zerbini
gr-qc