Asymptotic formulas for the solutions of the equation (py')' + qy = 0 Ráb, M. — 1967 Differential Equations and Their Applications
Asymptotic formulas for the solutions of linear differential equations of the second order Ráb, M. — 1963 Differential Equations and Their Applications
Stability and asymptotic properties of dynamical systems in the plane Ráb, M.; Kalas, J. — 1990 Equadiff 7