Lukashevich, N. A.; Martynov, I. P. Riccati equation and special third-order systems without movable critical points. (English. Russian original) Zbl 0911.34028 Differ. Equations 33, No. 5, 710-712 (1997); translation from Differ. Uravn. 33, No. 5, 707-708 (1997). The paper deals with the third-order system of nonlinear ODEs \(\alpha'= a_2 (\alpha \gamma-\beta)+\varphi (\alpha)\), \(\beta'=(a_1 \alpha+a_2\gamma +b_1+b_2)\beta+c_1 \gamma+c_2\alpha\), \(\gamma'=a_1(\alpha\gamma-\beta)+\psi(\gamma)\), whose coefficients \(a_i, b_i,c_i\), \(i=1,2\), are analytic functions of \(t\in D\), \(a_1a_2\not\equiv 0\), and \(\varphi(\alpha)\), \(\psi(\gamma)\) are second-degree polynomials in \(\alpha\) and \(\gamma\), respectively. The authors prove that this system has no movable critical points and use its solutions \(\alpha,\beta\), and \(\gamma\) for finding a relationship among solutions to two corresponding Riccati equations. Reviewer: V.Chernyatin (Szczecin) MSC: 34C05 Topological structure of integral curves, singular points, limit cycles of ordinary differential equations 34A34 Nonlinear ordinary differential equations and systems, general theory 34B30 Special ordinary differential equations (Mathieu, Hill, Bessel, etc.) Keywords:analytic coefficients; nonlinear ODEs; second-degree polynomials PDF BibTeX XML Cite \textit{N. A. Lukashevich} and \textit{I. P. Martynov}, Differ. Equations 33, No. 5, 710--712 (1997; Zbl 0911.34028); translation from Differ. Uravn. 33, No. 5, 707--708 (1997)