1. Theorems on differential inequalities for second order functional differential equations;Bainov;Glas. Mat. Ser. III,1994
2. Nonlinear eigenvalue problems involving two classes of functional differential equations;Davis;Houston J. Mathematics,2000
3. Eigenvalue problems for nonlinear differential equations;Henderson;Communications on Applied Nonlinear Analysis,1996
4. Positive solutions and nonlinear eigenvalue problems for functional differential equations;Henderson;Appl. Math. Lett.,1999