On the spectrum of sums of generators in a finite group
S. P. Strunkov

References
1.	Kostrikin A. I., “O probleme Bernsaida”, Izv. AN SSSR. Ser. matem., 23:1 (1959), 3–34
2.	Kostrikin A. I., Vokrug Bernsaida, Nauka, M., 1988
3.	Gantmakher F. R., Teoriya matrits, Nauka, M., 1966