Petrozavodsk AlkinRuslan V. Petrozavodsk State University, 33, Lenina ave., Petrozavodsk, 185910, Russia ruslan5.ru@yandex.ru Read more about Alkin Ruslan V. KirillovAleksandr N. Petrozavodsk State University, 33, Lenina ave., Petrozavodsk, 185910, Russia kirillov@krc.karelia.ru Read more about Aleksandr N. Kirillov
