1. Ibodullaev M. I., Tovbaev A. N., Esenbekov A. K., Self-oscillations at the frequency of sub harmonics in nonlinear electric chains and systems// E3S Web of Conferences Volume 138 (2019) International Scientific Conference “Construction and Architecture: Theory and Practice for the Innovation Development”:(CATPID-2019) Volume 138 (2019)
2. Ibadullaev M., Tovbaev A. N., Research of ferroresonance oscillations at the frequency of sub harmonics in three-phase non-linear electric circuits and systems// Rudenko International Conference on Methodological Problems in Reliability Study of Large Energy Systems, RSES 2020; Kazan; Russian Federation; 21-26 September 2020.Scopus: E3S Web of Conferences Volume 216, 14 December 2020.
3. Mannapov A. N. Musabekov P. Investigation of a three-phase electroferromagnetic circuit with a ferromagnetic coupling in the excitation mode of the second sub harmonic/ / V. Sb. “Questions of the theory of nonlinear circuits and processes”, - Tashkent, 1979. Vol. 269. –p.13–19
4. Joe Perez, Understanding sub-harmonics P. E., ERL Phase Power Technologies, Winnipeg, MB, Canada 2014 p.13 http://www.erlphase.com/downloads/application_notes/Understanding_Sub_Harmonics.pdf.
5. Sayenko Yu. L., Popov A. S., Investigation of ferroresonance processes taking into account the variation of the weber-ampere characteristics of voltage transformers/ Electric power and electromechanical systems: a collection of scientific works. - 2012. - No 736. - p. 123–132.