1. Periodic Differential Equations: an Introduction to Mathieu, Lamé and Allied Functions;Arscott,1964
2. Discrete and Continuous Boundary Problems;Atkinson,1964
3. Multiparameter Eigenvalue Problems, Vol. 1: Matrices and Compact Operators;Atkinson,1972
4. A variational approach to multiparameter eigenvalue problems for matrices;Binding;SIAM J. Math. Anal.,1977
5. A variational approach to multiparameter eigen-value problems in Hilbert space;Binding;SIAM J. Math. Anal.,1978