Inequalities of M.G. Krein, Yu.V. Linnik and E.A. Gorin for positive   definite functions
  We investigate inequalities of M.G. Krein, Yu.V. Linnik and E.A. Gorin for positive definite functions. Modifications and generalizations of these inequalities are proved. We also prove that multipoint E.A. Gorin's inequality follows from two--point M.G. Krein's inequality. 
A.B. Pevnyi, S.M. Sitnik
math.CA