P.B.Wiegmann

On the singular spectrum of the Almost Mathieu operator. Arithmetics and Cantor spectra of integrable models

P.B.Wiegmann, 1999, hep-th/9909083.

Algebraization of difference eigenvalue equations related to $U_q(sl_2)$

A.V.Zabrodin, P.B.Wiegmann, 1995, cond-mat/9501129.

Principal Chiral Field at Large N

V.A.Kazakov, P.B.Wiegmann, V.A.Fateev, 1994, hep-th/9403099.