1. [1] Kametaka, Y., Watanabe, K. and Nagai, A., The best constant of Sobolev inequality in an n dimensional Euclidean space, Proc. Japan Acad. Ser. A, 81 (2005), 57-60.
2. [2] Kametaka, Y., Yamagishi, H., Watanabe, K., Nagai, A. and Takemura, K., Riemann zeta function, Bernoulli polynomial and the best constant of Sobolev inequality, Sci. Math. Jpn., 65 (2007), 333-359.
3. [3] Komatsu, Y., Special functions [in Japanese], Asakura.
4. [4] Graham, R. L., Knuth, D. E. and Patashnik, O., Concrete Mathematics, Addison Wesley, 1994.
5. [5] Talenti, G., The best constant of Sobolev inequality, Ann. Mat. Pura Appl., 110 (1976), 353-372.