1. Application of the Ritz method to non-standard eigenvalue problems;Andrew;J. Austral. Math. Soc.,1969
2. Variational solution of some nonlinear eigenvalue problems, I;Andrew;J. Math. Anal. Appl.,1970
3. Non-radial oscillations of massive stars by variational methods;Andrew;Acad. Roy. Belg. Bull. Cl. Sci.,1968
4. Introduction to Matrix Analysis;Bellman,1960
5. Approximation and estimates for eigenvalues;Fichera,1966