[1] J. Böhm: The Smoothing Calculus (in Czech). SNTL, Prague 1964.

[2] R. Deutsch: Estimation Theory. Prentice-Hall, 1965. MR 0192572 | Zbl 0141.34304

[3] F. R. Gantmacher: Matrizenrechung (Translation from Russian). DVW, Berlin 1958.

[4] J. Mařík: On Polynomials with Real Roots (in Czech). Čs. pro pěstování matematiky 89 (1964), p. 5. MR 0180548

[5] J. Nekolný: Simultaneous Check of Stability and Quality of Control (in Czech). Comp. Souhrn prací o automatizaci. Publishing House of the Czechoslovak Academy of Sciences, Prague 1961.

[6] J. Štěpán: The Identification of Controlled Systems and the Limit of Stability. Compendium: Identification in Automatic Control Systems. Academia, Prague 1967.

[7] J. Štěpán: The Approximation of Transfer Functions by means of Dominant Roots (in Czech). Automatizace (1960), no. 7.

[8] J. Štěpán: Approximation of Functions in Control Problems (in Czech). Kybernetika (1967), no. 3.