1. L. D. Landau and E. M. Lifshitz, Course of Theoretical Physics, Vol. 3: Quantum Mechanics: Nonrelativistic Theory (Pergamon, Oxford, 1977), p. 75.
2. M. B. Vinogradova, O. V. Rudenko, and A. P. Sukhorukov, The Wave Theory (Nauka, Moscow, 1990), p. 168.
3. A. C. Kak and M. Slaney, Principles of Computerized Tomographic Imaging (Soc. Ind. Appl. Math., Philadelphia, 2001), p. 205.
4. A. P. Veselov and S. P. Novikov, Sov. Math. Dokl. 30, 705 (1984).
5. P. G. Grinevich, A. E. Mironov, and S. P. Novikov, Russ. Math. Surv. 65, 580 (2010).