1. A. Grzegorczyk, “Undecidability of some topological theories,” Fundam. Math. 38, 137–152 (1951).
2. M. O. Rabin, “Decidable theories” In: Handbook of Mathematical Logic, pp. 595–630, North Holland, Amsterdam etc. (1999).
3. J. Flum and M. Ziegler, Topological Model Theory, Springer, Berlin etc. (1980).
4. V. S. Amstislavskiy, “Elementary theories of continuous functions spaces” [in Russian], Vestn. Novosib. Gos. Univ., Ser. Mat. Mekh. Inform. 12, No. 3, 22–34 (2012); English transl.: J. Math. Sci., New York 202, No. 1, 13–24 (2014).
5. R. I. Soare, Recursively Enumerable Sets and Degrees: A Study of Computable Functions and Computably Generated Sets, Springer, Berlin (1987).