  We discuss the integrability of the Bosonic and Grassmannian massive Thirring
models in the presence of defects through the inverse scattering approach. We
present a general method to compute the generating functions of modified
conserved quantities for any integrable field equation associated to the m x m
spectral linear problem. We apply the method to derive in particular the defect
contributions for the number of occupation, energy and momentum of the massive
Thirring models.
