C. Herdeiro, I. Perapechka, E. Radu, Ya. Shnir, “Gravitating solitons and black holes with synchronised hair in the four dimensional O(3) sigma-model”, J. High Energ. Phys., 2019, no. 2, 2019, 111
K. Arthur, D.H. Tchrakian, “SO(3) gauged soliton of an O(4) sigma model on 3”, Physics Letters B, 378, no. 1-4, 1996, 187
H.S. Sharatchandra, J. Trampetić, “Extracting hidden fermions from bosonic effective theories”, Physics Letters B, 144, no. 5-6, 1984, 433
N.S. Manton, P.J. Ruback, “Skyrmions in flat space and curved space”, Physics Letters B, 181, no. 1-2, 1986, 137
L.A. Ferreira, Ya. Shnir, “Exact self-dual skyrmions”, Physics Letters B, 772, 2017, 621
V. N. Romanov, I. V. Frolov, A. S. Schwarz, “Spherically symmetric solitons”, Theor Math Phys, 37, no. 3, 1978, 1038
A.A. Andrianov, “Bosonization in four dimensions due to anomalies and an effective lagrangian for pseudoscalar mesons”, Physics Letters B, 157, no. 5-6, 1985, 425
R. Rennie, “Geometry and topology of chiral anomalies in gauge theories”, Advances in Physics, 39, no. 6, 1990, 617
M.M. Enikova, V.I. Karloukovski, C.I. Velchev, “Exact finite-energy solutions in non-linear SU(2) × SU(2) and SU(2) × SU(1, 1) chiral theories”, Nuclear Physics B, 151, 1979, 172
TAO XU, HONGLING SU, GANG ZHOU, XIWEI HU, “ASPECT ON BIFURCATION OF ELECTROMAGNETIC VORTEX LINE”, Mod. Phys. Lett. A, 21, no. 17, 2006, 1369