An integral criterion for oscillation of linear differential equations of second order

It is proved that if for some n>2 the function x^1–nA_n(x), where A_n(x) is the n-th primitive ofa(x), is not bounded above, then the equation y +a(x)y = 0 oscillates.Translated from Matematicheskie Zametki, Vol. 23, No. 2, pp. 249–251, February, 1978.In conclusion, I thank R. S. Ismagilov for useful discussions about the problem of osillation.