Aromaticity of the planar hetero[8]circulenes and their doubly charged ions: NICS and GIMIC characterization / G. V. Baryshnikov, R. R. Valiev, N. N. Karaush, B. F. Minaev // Physical chemistry chemical physics. 2014. Vol. 16, № 29. P. 15367-15374. URL: http://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000494603