1. Baribeau, L., Rivard, P., Wegert, E.: On hyperbolic divided differences and the Nevanlinna-Pick problem. Comput. Methods Funct. Theory 9, 391–405 (2009)
2. Beardon, A.F., Minda, D.: A multi-point Schwarz-Pick lemma. J. Anal. Math. 92, 81–104 (2004)
3. Cho, K.Y., Kim, S.-A., Sugawa, T.: On a multi-point Schwarz-Pick lemma. arXiv:
1102.0337v1
[math.CV]
4. Graduate Texts in Mathematics;J.B. Garnett,2007
5. Kim, S.-A., Sugawa, T.: Invariant differential operators associated with a conformal metric. Mich. Math. J. 55(2), 459–479 (2007)