R. Wellman

A General Left-Definite Theory for Certain Self-Adjoint Operators with Applications to Differential Equations

Lance L. Littlejohn, L. Littlejohn, R. Wellman, 2002 .

The left-definite spectral theory for the classical Hermite differential equation

Lance L. Littlejohn, W. N. Everitt, L. Littlejohn, 2000 .

Legendre polynomials, Legendre--Stirling numbers, and the left-definite spectral analysis of the Legendre differential expression

Lance L. Littlejohn, W. N. Everitt, L. Littlejohn, 2002 .

Orthogonal polynomial solutions of linear ordinary dierential equations

Kil Hyun Kwon, Lance L. Littlejohn, W. N. Everitt, 2001 .

Jacobi-Stirling numbers, Jacobi polynomials, and the left-definite analysis of the classical Jacobi differential expression

Gangjoon Yoon, Kil Hyun Kwon, Lance L. Littlejohn, 2007 .