1. Oscillatory solutions and extremal points for a linear differential equation;Elias;Arch. Rational Mech. Anal.,1979
2. A classification of the solutions of a differential equation according to their asymptotic behavior;Elias,1979
3. A classification of the solutions of a differential equation according to their behavior at infinity, II;Elias,1985
4. Boundary value problems for nth order difference equations;Hankerson,1986
5. On a theorem of Elias for difference equations;Hankerson,1987