1. Theory of Ordinary Differential Equations;Coddington,1955
2. Numerical investigations into the Stokes Phenomenon. I and II;Emamzadeh;J. Inst. Math. Appl.,1977
3. Asymptotic Expansions;Erdélyi,1956
4. Asymptotic behavior as Λ ŕ ∞ of the solution of the equation w”(z) - p(z,Λ)w(z) =0 in the complex z-plane;Evgrafov;Russian Math. Surveys,1966
5. Asymptotics of the discrete spectrum of the operator w”(x) - Λ2p(x)w(x);Fedoryuk;Mat. Sb.,1965