1. Computing eigenvalues and Fučík-spectrum of the radially symmetric p-Laplacian;Brown;J. Comput. Appl. Math.,2002
2. Eigenvalues of the radially symmetric p-Laplacian in Rn;Brown;J. London Math. Soc.,2004
3. M.S.P. Eastham, The asymptotic solution of linear differential systems, London Mathematical Society Monographs, vol. 4, Clarendon Press, Oxford, 1989.
4. Direct Methods of Qualitative Spectral Analysis of Singular Differential Operators;Glazman,1965
5. Some remarkable sine and cosine functions;Lindqvist;Ricerche Mat.,1995