1. Bārzdiņš, J.: Two theorems on the limiting synthesis of functions. In: Theory of Algorithms and Programs, vol. 1, pp. 82–88. Latvian State University (1974) (in Russian)
2. Bārzdiņš, J.: Inductive inference of automata, functions and programs. In: Proceedings of the 20th International Congress of Mathematicians, Vancouver, pp. 455-560 (1974) (in Russian)
3. English translation in American Mathematical Society Translations: Series 2 109, 107-112 (1977)
4. Blum, L., Blum, M.: Towards a mathematical theory of inductive inference. Information and Control 28, 125–155 (1975)
5. Feldman, J.: Some decidability results on grammatical inference and complexity. Information and Control 20, 244–262 (1972)