S.Khoroshkin

Generalized Hirota Equations and Representation Theory. I. The case of $SL(2)$ and $SL_q(2)$"

A.Morozov, A.Mironov, A.Gerasimov, 1994, hep-th/9405011.

Intertwining operators and Hirota bilinear equations

S.Kharchev, S.Khoroshkin, D.Lebedev, 1995, q-alg/9506022.