1. Discrete and Continuous Boundary Problems,;Atkinson,1964
2. On the spectrum of ordinary second order differential operators;Chaudhuri;Proc. P.oyal Society Edinburgh,1967
3. Fourth order singular differential equations;Everitt;Math. Ann.,1963
4. Singular differential equations, I; the even order case;Everitt;Math. Ann.,1964
5. Integrable-square, analytic solutions of odd-order, formally symmetric, ordinary differential equations;Everitt;Proc. London Math. Soc. (3),1972