https://www.scirp.org/reference/ReferencesPapers?ReferenceID=2224301
Fogel, M.B., Trullinger, S.E., Bishop, A.R. and Krumhans, J.A. (1977) Dynamics of sine-Gordon...
Fogel, M.B., Trullinger, S.E., Bishop, A.R. and Krumhans, J.A. (1977) Dynamics of sine-Gordon Solitons in the Presence of Perturbations. Physical Review B, 15,...