1. Perturbation Theory for Linear Operators;Kato,1976
2. The association of resonance states with incomplete spectrum of finite complex-scaled Hamiltonian matrices;Moiseyev;Phys. Rev. A,1980
3. Pairs of matrices with property L;Motzkin;Trans. Amer. Math. Soc.,1952
4. Pairs of matrices with property L. II;Motzkin;Trans. Amer. Math. Soc.,1955
5. Asymptotic Expansions for Ordinary Differential Equations;Wasow,1976