8th International Colloquium on Differential Equations, Plovdiv, Bulgaristan, 18 - 23 Ağustos 1997, ss.9-16
Let mu(1), mu(2),..., mu(n),... be the Dirichlet spectrum of the operator -d(2)/dx(2) + q(x) acting on L-2(0,pi). In the special case where q(x) = 0, mu(n) = n(2). In the [1] and others discovered the asymptotic formula