[1] ポントリャーギン : 「常微分方程式新版」 (木村俊房校閲・千葉克裕訳, 共立出版, 1968) p.118.
[2] E. T. Whittaker and G. N. Watson : A Course of Modern Analysis 4th ed. (1927), (Reprinted, Cambridge at the University Press, 1965).
[3] Albert Messiah : Quantum Mechanics Volume I, translated from the French by G. M. Temmer (John Wiley & Sons, Inc., Fourth printing 1966), p.109.
[4] L. D. Landau and E. M. Lifshitz : Quantum Mechanics, Non-relativistic Theory (transl. by J. B. Sykes and J.S. Bell, Pergamon, Oxford, 2nd ed. 1965), p.477.
[5] Eugene Merzbacher : Quantum Mechanics (John Wiley&Sons, Inc., 1961 ; Second Edition 1970), p.509.
[6] Hermann Weyl : the theory of groups and quantum mechanics (Dover, 1950), p.114.
[7] 山内恭彦・杉浦光夫 : 「連続群論入門」 (培風館, 1960), p.29.
[8] G. Birkhoff and S. Mac Lane : A Survey of Modern Algebra, 4th ed. (Macmillan Publishing Company 1977), p.134.
[9] 佐竹一郎 : 「行列と行列式」 (裳華房, 1958 ; 第9版 1963), 第II章§1, §2 例3.
[10] Eugene Merzbacher : Quantum Mechanics (John Wiley&Sons, Inc., 1961 ; Second Edition 1970), p.96.
[11] 江沢洋 : 「量子力学 (I) 」 (裳華房, 2002).
[12] 岩波講座現代物理学の基礎 [第2版] 4量子力学 II (湯川秀樹・豊田利幸編集, 岩波書店, 1978), 第16章 (江沢洋執筆) §16.4.
[13] Tosio Kato : Perturbation Theory for Linear Operators (Springer-Verlag, 2nd ed., 1976).
[14] D. L. Kreider, R. G. Kuller, D. R. Ostberg and F. W. Perkins : An Introduction to Linear Analysis (Addison-Wesley Publishing Company, Inc., 1966), pp.231-233.