1. A. M. Kagan, Yu. V. Linnik, and S. R. Rao, Characterization Problems in Mathematical Statistics [in Russian], Nauka, Moscow (1972).
2. E. Hewitt and K. Ross, Abstract Harmonic Analysis. Vol. 1, 2 [Russian translation], Nauka, Moscow (1975).
3. G. M. Fel'dman, “The Cauchy distribution on abelian groups and its characterization,” Dokl. Akad. Nauk SSSR,309, No. 1, 46–49 (1989).
4. G. M. Fel'dman, “On the characterization of a Gaussian distribution on groups by the equidistribution of a monomial and a linear statistics,” Ukrain. Mat. Zh.,41, No. 8, 1112–1118 (1989).
5. G. M. Fel'dman, “On the groups admitting the characterization of a Gaussian distribution by the equidistribution of a monomial and a linear statistics,” Ukrain. Mat. Zh.,42, No. 1, 139–142 (1990).