Phase portraits for quadratic systems with a higher order singularity with two zero eigenvalues (Q752274)

For the quadratic system of ODE with right-hand sides consisting of polynomials with real coefficients of degree 2 and with a higher order singularity having two zero eigenvalues the phase portraits are given. These phase portraits are characterized by the number, position and character of the singular points, by the number and position of periodic solutions, by the position of the separatrices and by the behaviour at infinity.