... regular boundary value problems,” European Journal of Pure and Applied Mathematics, vol 1, no 2, pp 51–60, 2008 K R Mamedov and H Menken, Asymptotic formulas for eigenvalues and eigenfunctions of ... Sturm-Liouville Operators and Applications, vol 22 of Operator Theory: Advances and Applications, Birkh¨ user, Basel, Switzerland, 1986 a M A Naimark, Linear Differential Operators Part 1, Frederick Ungar, New ... Case Assume that q x ∈ C 0, π and the condition q π − q / holds Based on the asymptotic expressions of the fundamental solutions of 1.1 and the asymptotic formulas for eigenvalues of the boundary-value...