1. Disconjugacy;Coppel,1971
2. Green's functions for a nondisconjugate differential operator;Elias;J. Differential Equations,1980
3. Oscillation Theory for Two-Term Differential Equations;Elias,1997
4. Multipoint boundary value problems for ordinary differential systems;Eloe;J. Differential Equations,1994
5. A singular boundary value problem for a right disfocal linear differential operator;Eloe;Dynam. Systems Appl.,1996