1. Analysis in the computable number field;Aberth;J. Assoc. Comput. Mach.,1968
2. Isomorphisms of ω-groups;Applebaum;Notre Dame J. Formal Logic,1971
3. Algebraische Konstruktion reeller Körper;Artin;Abh. Math. Sem. Univ. Hamburg,1927
4. Relativizations of the P = ? NP question;Baker;SIAM J. Comput.,1975
5. [5] P. Bernays and D. Hubert, Grundlagen der Mathematik, Vol. I, II, (1934, 1939), Grundlehren Math. Wiss.; [2nd. edn. (1968, 1970)].