1. Necessary conditions for the extension of linear operations;Akilov, G. P.;Doklady Akad. Nauk SSSR (N.S.),1948
2. On the extension of linear operations;Akilov, G. P.;Doklady Akad. Nauk SSSR (N. S.),1947
3. S. Banach, Théorie des opérations linéaires, Warsaw, 1932.
4. A characterization of 𝐶-spaces;Clarkson, James A.;Ann. of Math. (2),1947
5. M. M. Day, A review of Akilov’s "On the extension of linear operations," Mathematical Reviews vol. 9 (1948) p. 241.