Sine-Gordon multi-soliton form factors in finite volume
  Multi-soliton form factors in sine-Gordon theory from the bootstrap are compared to finite volume matrix elements computed using the truncated conformal space approach. We find convincing agreement, and resolve most of the issues raised in a previous work. 
G. Z. Feher, T. Palmai and G. Takacs
hep-th cond-mat.stat-mech