  The NLIE (the non-linear integral equation equivalent to the Bethe Ansatz
equations for finite size) is generalized to excited states, that is states
with holes and complex roots over the antiferromagnetic ground state. We
consider the sine-Gordon/massive Thirring model (sG/mT) in a periodic box of
length $L$ using the light-cone approach, in which the sG/mT model is obtained
as the continuum limit of an inhomogeneous six vertex model. This NLIE is an
useful starting point to compute the spectrum of excited states both
analytically in the large $L$ (perturbative) and small $L$ (conformal) regimes
as well as numerically.
