1. Abramowitz, M., Stegun, I.A.: Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables. National Bureau of Standards Applied Mathematics Series, No. 55, p. 1046. U. S. Government Printing Office, Washington, D.C. (1964). For sale by the Superintendent of Documents
2. Aigner, M.: Markov’s Theorem and 100 Years of the Uniqueness Conjecture, p. 257. Springer, Cham (2013). https://doi.org/10.1007/978-3-319-00888-2. A mathematical journey from irrational numbers to perfect matchings
3. Andersen, N., Lagarias, J.C., Rhoades, R.C.: Shifted polyharmonic Maass forms for $${{\rm PSL}}(2,{\mathbb{Z} })$$. Acta Arith. 185(1), 39–79 (2018). https://doi.org/10.4064/aa170905-7-3
4. Arakawa, T.: Dirichlet series $$\sum ^\infty _{n=1}{\rm cot}\,\pi n\alpha / n^s,$$ Dedekind sums, and Hecke $$L$$-functions for real quadratic fields. Comment. Math. Univ. St. Paul. 37(2), 209–235 (1988)
5. Asai, T.: The reciprocity of Dedekind sums and the factor set for the universal covering group of $${\rm SL}(2,{\mathbb{R} })$$. Nagoya Math. J. 37, 67–80 (1970)