1. L. A. Khalfin, Pis'ma Zh. Eksp. Teor. Fiz.,7, 341 (1968); ?Admissible mass distributions of unstable particles (resonances),? Report Presented at 14th International Conf. on High-Energy Physics, Vienna (1968), OIYaI R-0470 [in Russian], Dubna (1968).
2. L. A. Khalfin, Investigations in the Quantum Theory of Unstable Particles, Doctoral Dissertation [in Russian], OIYaI, Dubna (1974).
3. L. A. Khalfin, Pis'ma Zh. Eksp. Teor. Fiz.,3, 129 (1966); ?Nonexponential law of decay, mass filter, and the problem of CP invariance,? Report at Session of the Nuclear Physics Branch of the Academy of Sciences of the USSR (1968).
4. Christenron et al., Phys. Rev. Lett.,13, 138 (1964).
5. L. B. Okun', Usp. Fiz. Nauk,89, 603 (1966); J. Bell and J. Steinberger, Lectures at Oxford Conference on Elementary Particles (1965); S. M. Bilen'kii, Fiz. Elem. Chastits At. Yadra,1, 129 (1970); R. I. Oakes, Preprint DESY 71/53 (1971); C. Rubbis, Proc. of the Seventeenth Conf. on High Energy Phys.,4, 157 (1972).