ノルム多元体
121. ISBN 0-387-96980-2. Zbl 0669.17001. https://books.google.com/books?btnG=Google+Search&as_epq=Normed+algebras+with+an+identity.+Hurwitz's+theorem
↑ Shapiro, Daniel B. (2000). “Appendix to Chapter 1. Composition algebras”. Compositions of quadratic forms. de Gruyter Expositions in Mathematics. 33. Berlin: Walter de Gruyter. pp. 21 ff. ISBN 3-11-012629-X. Zbl 0954.11011. https://books.google.co.jp/books?id=qrFhUda9JbkC&pg=PA21&redir_esc=y&hl=ja
↑ Joe Roberts (1992). “Square identities”. Lure of the integers. Cambridge University Press. ISBN 0-88385-502-X. https://books.google.co.jp/books?id=DvX90EKMxGwC&pg=PA93&redir_esc=y&hl=ja
↑ Lam (2005) p.130
↑ Rajwade (1993) p.3