1. Nonlinear elliptic problems in annular domains;Bandle;J. Differential Equations,1987
2. Semilinear elliptic problems in annular domains;Bandle;J. Appl. Math. Phys.,1989
3. Positive solutions for singular higher order nonlinear equations;Chyan;Differential Equations Dynam. Systems,1994
4. Positive solutions for higher order differential equations;Eloe;Elec. J. Differential Equations,1995
5. On the existence of positive solutions of ordinary differential equations;Erbe;Proc. Amer. Math. Soc.,1994