Regular third-order boundary value problems

<i>Theory of Ordinary Differential Equations</i>

Earl A. Coddington, Norman Levinson, T. Teichmann · Physics Today · 1956 · 6.2K citations

Spectral Theory, Complex Variable, Function Theory +7

Theory of ordinary differential equations

H.L. Platzer · Journal of the Franklin Institute · 1956 · 5.6K citations

Oscillation Theory, Ordinary Differential Equations, Nonlinear Equation +1

Eigenvalues of Regular Sturm–Liouville Problems

Qingkai Kong, Anton Zettl · Journal of Differential Equations · 1996 · 155 citations

Spectral Theory, Potential Theory, Regular Sturm–liouville Problems

Formally self-adjoint quasi-differential operators

Anton Zettl · Rocky Mountain Journal of Mathematics · 1975 · 111 citations · Full text

Linear Operator, Global Analysis, Self-adjoint Quasi-differential Operators +2

Dependence of the nth Sturm–Liouville Eigenvalue on the Problem

Qingkai Kong, Hongyou Wu, Anton Zettl · Journal of Differential Equations · 1999 · 107 citations

Spectral Theory, Nth Sturm–liouville Eigenvalue, Perturbation Method