참고문헌
- Symposium on Spectral Theory and Differential Problems VApproximation methods for eigenvalues of completely continuous symmetric operators N.Aronszajn
- Arch. Rat. Mech. Anal. v.10 TLower bounds to eigenvalues using operator decompositions of the form B*B N.Bazley;D.W.Fox
- Methods of mathematical physics v.1 R.Courant;D.Hilbert
- J. Korean Math. Sci. v.31 On lower bounds of eigenvalues for self adjoin operators G.Lee
- Methods of Intermediate Problems for Eigenvalues: Theory and Ramifications A.Weinstein;W.Stenger