1. Yu. N. Subbotin, S. I. Novikov, and V. T. Shevaldin, Tr. Inst. Mat. Mekh. Ural. Otd. Ross. Akad. Nauk 24 (3), 200–225 (2018).
2. Yu. N. Subbotin, Tr. Mat. Inst. im. V.A. Steklova Akad. Nauk SSSR 78, 24–42 (1965).
3. N. P. Korneichuk, Exact Constants in Approximation Theory (Nauka, Moscow, 1987; Cambridge Univ. Press, Cambridge, 1991).
4. Yu. N. Subbotin, Tr. Mat. Inst. im. V.A. Steklova Akad. Nauk SSSR 88, 30–60 (1967).
5. K. Dilcher, NIST Handbook of Mathematical Functions (US Dept. of Commerce, Washington, 2010).