Real algebras with a Hilbert space structure

Ambrose, W., Structure theorems for a special class of Banach algebras. Trans. Amer. Math. Soc.57, 364–386 (1945).

Ingelstam, L., Hilbert algebras with identity. Bull. Amer. Math. Soc.69, 794–796 (1963).

—, Real Banach algebras. Ark. Mat.5, 239–270 (1964).

— Non-associative normed algebras and Hurwitz' problem. Ark. Mat.5, 231–238 (1964).

Loomis, L. H., An Introduction to Abstract Harmonic Analysis. Van Nostrand, Princeton, 1953.

Rajagopolan, M.,H *-algebras. J. Indian Math. Soc. (N.S.),25, 1–25 (1961).

Rickart, C. E., General Theory of Banach Algebras. Van Nostrand, Princeton, 1960.

Saworotnow, P. P., On the condition of continuity of multiplication in anH *-algebra. Notices Amer. Math. Soc.10, 195 (1963).

—, On a generalization of the notion ofH *-algebra. Proc. Amer. Math. Soc.8, 49–55 (1957).

Smiley, M. F., RightH *-algebras. Proc. Amer. Math. Soc.,4, 1–4 (1953).