1. Podlovchenko, R.I., Hierarchy of Program Models, Programmirovanie, 1981, no. 2, pp. 3–14.
2. Podlovchenko, R.I., Semigroup Program Models, Programmirovanie, 1981, no. 4, pp. 3–13.
3. Podlovchenko, R.I. and Alanakyan, N.A., Regular Program Models, Programmirovanie, 1993, no. 4, pp. 3–11.
4. Yanov, Yu.I., On Logical Schemes of Algorithms, Problemy kibernetiki, 1958, vol. 1, pp. 79–127.
5. Podlovchenko, R.I., Abstract Programs with Procedures and Finite Push-Down Automata, in Intellektual’nye sistemy (Intelligent Systems), Moscow: Mosk. Gos. Univ., 1997, vol. 2, nos. 1–4, pp. 275–295.