1063/1.1722572. (原始内容 (PDF)存档于2017-08-11). Claude Cohen-Tannoudji, BernardDiu, Franck Laloë: Quantenmechanik 1/2. 2. Auflage. Walter de Gruyter, Berlin
Pomerans, Harper & Row, New York, 1971, pp. 63–64. Claude Cohen-Tannoudji, BernardDiu and Franck Laloë, Mecanique quantique (see also Quantum Mechanics translated