The ground state energies of the [Formula: see text] coset theories, perturbed by the [Formula: see text] operator, and those of the sine-Gordon theory, for special values of the coupling constant in the attracting regime, are the same. In the first part of this paper we extend these results to the [Formula: see text] cases. In the second part, we analyze the algebraic Bethe ansatz procedure for special points in the repulsive region. We find a one-to-one “duality” correspondence between these theories and those studied in the first part of the paper. We use the gluing procedure at the massive node proposed by Fendley and Intriligator in order to obtain the TBA systems for the generalized parafermionic supersymmetric sine-Gordon model. In the third part we propose the TBA equations for the whole class of perturbed coset models [Formula: see text] with the operator [Formula: see text] and G a nonsimplylaced group generated by one of the [Formula: see text], ℱ4, ℬn, [Formula: see text] algebras.