1. Pure and Applied Mathematics, Vol. XV;Bishop, Richard L.,1964
2. Quelques propriétés globales des espaces de Riemann;Preissmann, Alexandre;Comment. Math. Helv.,1943
3. P. A. Smith, “Fixed points of periodic transformations,” Appendix B in Lefschetz, Algebraic topology, Amer. Math. Soc. Colloq. Publ., vol. 27, Amer. Math. Soc., Providence, R. I., 1942. MR 4, 84.