V. Q. Phong and N. M. Anh, Two Electro-weak Phases in the \(SU(2)_1 \otimes SU(2)_2 \otimes U(1)_Y\) Model, Comm. Phys. 29 (2019) 149. DOI: https://doi.org/10.15625/0868-3166/29/2/13528.