Inverse Theorem on Row Sequences of Linear Pad\'e-orthogonal   Approximation
  We give necessary and sufficient conditions for the convergence with geometric rate of the denominators of linear Pad\'e-orthogonal approximants corresponding to a measure supported on a general compact set in the complex plane. Thereby, we obtain an analogue of Gonchar's theorem on row sequences of Pad\'e approximants. 
N. Bosuwan and G. L\'opez Lagomasino
math.CV