1. Yu. I. Zhuravlev, “Correct algebras for sets of incorrect (heuristic) algorithms. Part 1,” Kibernetika, No. 4, 5–17 (1977).
2. Yu. I. Zhuravlev, “Correct algebras for sets of incorrect (heuristic) algorithms. Part 2,” Kibernetika, No. 6, 21–27 (1977).
3. Yu. I. Zhuravlev, “Correct algebras for sets of incorrect (heuristic) algorithms. Part 3,” Kibernetika, No. 2, 35–43 (1978).
4. Yu. I. Zhuravlev, “On algebraic approach for solving recognition and classification problems,” in Problems of Cybernetics (Nauka, Moscow, 1978), issue 33, pp. 5–68 [in Russian].
5. K. V. Rudakov, “On some universal limitations for classification algorithms,” Zh. Vychisl. Mat. Mat. Fiz. 26 (11), 1719–1729 (1986).