1. Actualit\'{e}s Scientifiques et Industrielles [Current Scientific and Industrial Topics], No. 1044;Bourbaki, N.,1948
2. Cohomology theory of a complex with a transformation of prime period and its applications;Nakaoka, Minoru;J. Inst. Polytech. Osaka City Univ. Ser. A,1956
3. On the homology characters of symmetric products;Richardson, Moses;Duke Math. J.,1935
4. Periodic transformations of complexes;Richardson, M.;Ann. of Math. (2),1938
5. On universal mappings and free topological groups;Samuel, P.;Bull. Amer. Math. Soc.,1948