Manifestation of metric renormalization in quantum $R^2$--gravity
  The renormalization group method in $R^2$-gravity without matter fields is discussed. A criterion for the existence of the renormalization constant for the metric has been found, two-loop higher order poles have been calculated, a relation which allows us to find the one-loop renormalization constant of the Newtonian constant has been suggested. 
M.Yu.Kalmykov