1. Z. I. Yakshtas, ?On the bias of the sphere in the space C,? Uchen. Zap. Kalinin. Ped. Inst.,52, 208?212 (1967).
2. A. I. Romanov, ?On the bias of the unit sphere in the space L? (?>1),? Uchen. Zap. Kalinin. Ped. Inst.,52, 101?106 (1967).
3. B. N. Delone and D. A. Raikov, Analytical Geometry [in Russian], Vol. I, Moscow-Leningrad (1948), p. 228.
4. M. M. Day, Normed Linear Spaces [Russian translation], Moscow (1961), p. 193.
5. P. Jordan and J. von Neumann, ?On inner products in linear metric spaces,? Ann. of Math. (12),36, 719?723 (1935).