Boundedness and oscillatoriness of solutions of the equation y" + a(x)g(y, y') + b(x)f(y)h(y') = 0 Pavel Šoltés — 1973 Annales Polonici Mathematici
Oscillatoriness of solutions of a second order differential equation Pavel Šoltés; Eva Švidroňová — 1985 Annales Polonici Mathematici