1. A. I. Aptekarev, Sharp constants for rational approximation of analytic functions, Sb. Math. 193(1) (2002), 1–72, English transl. in Math. Sb. 193(1–2) (2002), 1–72.
2. A. I. Aptekarev, Analysis of the matrix Riemann-Hilbert problems for the case of higher genus and asymptotics of polynomials orthogonal on a system of intervals. preprints of Keldysh Institute of Applied Mathematics, RAS, 2008. http://www.keldysh.ru/papers/2008/source/prep2008_28_eng.pdf .
3. A. I. Aptekarev and V. G. Lysov, Asymptotics of Hermite-Padé approximants for systems of Markov functions generated by cyclic graphs, Mat. Sb. 201(2) (2010), 29–78.
4. A. I. Aptekarev and W. Van Assche, Scalar and matrix Riemann-Hilbert approach to the strong asymptotics of Padé approximants and complex orthogonal polynomials with varying weight, J. Approx. Theory 129 (2004), 129–166.
5. R. J. Arms and A. Edrei. The Padé tables of continued fractions generated by totally positive sequences, Mathematical Essays dedicated to A. J. Macintyre, Ohio Univ. Press, Athens, Ohio, 1970, pp. 1–21.